From b7a4d12840ce37071dcb3d02a60d63721eae59ad Mon Sep 17 00:00:00 2001 From: Phil Shafer Date: Wed, 23 May 2018 01:12:17 +0000 Subject: [PATCH] Import libxo 0.9.0 --- configure.ac | 2 +- doc/Makefile.am | 5 + doc/_static/basic.css_t | 657 ++++++++++++ doc/_templates/localtoc.html | 14 + doc/api.rst | 1620 +++++++++++++++++++++++++++++ doc/conf.py | 178 ++++ doc/example.rst | 694 ++++++++++++ doc/faq.rst | 209 ++++ doc/field-formatting.rst | 370 +++++++ doc/field-modifiers.rst | 353 +++++++ doc/field-roles.rst | 310 ++++++ doc/format-strings.rst | 47 + doc/formatting.rst | 165 +++ doc/getting.rst | 185 ++++ doc/howto.rst | 394 +++++++ doc/index.rst | 53 + doc/intro.rst | 90 ++ doc/libxo-manual.html | 436 ++++---- doc/options.rst | 164 +++ doc/xo.rst | 125 +++ doc/xohtml.rst | 30 + doc/xolint.rst | 40 + doc/xopo.rst | 45 + libxo/libxo.c | 59 +- tests/core/saved/test_01.E.out | 4 + tests/core/saved/test_01.H.out | 2 +- tests/core/saved/test_01.HIPx.out | 8 + tests/core/saved/test_01.HP.out | 8 + tests/core/saved/test_01.J.out | 2 +- tests/core/saved/test_01.JP.out | 4 + tests/core/saved/test_01.T.out | 2 +- tests/core/saved/test_01.X.out | 2 +- tests/core/saved/test_01.XP.out | 4 + tests/core/saved/test_12.J.out | 2 +- tests/core/saved/test_12.JP.out | 40 +- tests/core/test_01.c | 3 + tests/gettext/saved/gt_01.J.out | 2 +- tests/gettext/saved/gt_01.JP.out | 2 +- 38 files changed, 6081 insertions(+), 249 deletions(-) create mode 100644 doc/_static/basic.css_t create mode 100644 doc/_templates/localtoc.html create mode 100644 doc/api.rst create mode 100644 doc/conf.py create mode 100644 doc/example.rst create mode 100644 doc/faq.rst create mode 100644 doc/field-formatting.rst create mode 100644 doc/field-modifiers.rst create mode 100644 doc/field-roles.rst create mode 100644 doc/format-strings.rst create mode 100644 doc/formatting.rst create mode 100644 doc/getting.rst create mode 100644 doc/howto.rst create mode 100644 doc/index.rst create mode 100644 doc/intro.rst create mode 100644 doc/options.rst create mode 100644 doc/xo.rst create mode 100644 doc/xohtml.rst create mode 100644 doc/xolint.rst create mode 100644 doc/xopo.rst diff --git a/configure.ac b/configure.ac index fab8c886706a..56b33c4c5e30 100644 --- a/configure.ac +++ b/configure.ac @@ -12,7 +12,7 @@ # AC_PREREQ(2.2) -AC_INIT([libxo], [0.8.4], [phil@juniper.net]) +AC_INIT([libxo], [0.9.0], [phil@juniper.net]) AM_INIT_AUTOMAKE([-Wall -Werror foreign -Wno-portability]) # Support silent build rules. Requires at least automake-1.11. diff --git a/doc/Makefile.am b/doc/Makefile.am index a00994cacb6f..0633db8fac07 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -68,3 +68,8 @@ else doc docs: @${ECHO} "The 'oxtradoc' tool is not installed; see libslax.org" endif + +SPHINX = python3.4 -msphinx + +html sphinx sphinx-html: + ${SPHINX} -M html ${srcdir} . diff --git a/doc/_static/basic.css_t b/doc/_static/basic.css_t new file mode 100644 index 000000000000..e8ebdc780dbc --- /dev/null +++ b/doc/_static/basic.css_t @@ -0,0 +1,657 @@ +/* + * basic.css + * ~~~~~~~~~ + * + * Sphinx stylesheet -- basic theme. + * + * :copyright: Copyright 2007-2017 by the Sphinx team, see AUTHORS. + * :license: BSD, see LICENSE for details. + * + */ + +/* -- main layout ----------------------------------------------------------- */ + +div.clearer { + clear: both; +} + +/* -- relbar ---------------------------------------------------------------- */ + +div.related { + width: 100%; + font-size: 90%; +} + +div.related h3 { + display: none; +} + +div.related ul { + margin: 0; + padding: 0 0 0 10px; + list-style: none; +} + +div.related li { + display: inline; +} + +div.related li.right { + float: right; + margin-right: 5px; +} + +/* -- sidebar --------------------------------------------------------------- */ + +div.sphinxsidebarwrapper { + padding: 10px 5px 0 10px; +} + +div.sphinxsidebar { + float: left; + width: {{ theme_sidebarwidth|toint }}px; + margin-left: -100%; + font-size: 90%; + word-wrap: break-word; + overflow-wrap : break-word; +} + +div.sphinxsidebar ul { + list-style: none; +} + +div.sphinxsidebar ul ul, +div.sphinxsidebar ul.want-points { + margin-left: 20px; + list-style: square; +} + +div.sphinxsidebar ul ul { + margin-top: 0; + margin-bottom: 0; +} + +div.sphinxsidebar form { + margin-top: 10px; +} + +div.sphinxsidebar input { + border: 1px solid #98dbcc; + font-family: sans-serif; + font-size: 1em; +} + +div.sphinxsidebar #searchbox input[type="text"] { + width: 170px; +} + +img { + border: 0; + max-width: 100%; +} + +/* -- search page ----------------------------------------------------------- */ + +ul.search { + margin: 10px 0 0 20px; + padding: 0; +} + +ul.search li { + padding: 5px 0 5px 20px; + background-image: url(file.png); + background-repeat: no-repeat; + background-position: 0 7px; +} + +ul.search li a { + font-weight: bold; +} + +ul.search li div.context { + color: #888; + margin: 2px 0 0 30px; + text-align: left; +} + +ul.keywordmatches li.goodmatch a { + font-weight: bold; +} + +/* -- index page ------------------------------------------------------------ */ + +table.contentstable { + width: 90%; + margin-left: auto; + margin-right: auto; +} + +table.contentstable p.biglink { + line-height: 150%; +} + +a.biglink { + font-size: 1.3em; +} + +span.linkdescr { + font-style: italic; + padding-top: 5px; + font-size: 90%; +} + +/* -- general index --------------------------------------------------------- */ + +table.indextable { + width: 100%; +} + +table.indextable td { + text-align: left; + vertical-align: top; +} + +table.indextable ul { + margin-top: 0; + margin-bottom: 0; + list-style-type: none; +} + +table.indextable > tbody > tr > td > ul { + padding-left: 0em; +} + +table.indextable tr.pcap { + height: 10px; +} + +table.indextable tr.cap { + margin-top: 10px; + background-color: #f2f2f2; +} + +img.toggler { + margin-right: 3px; + margin-top: 3px; + cursor: pointer; +} + +div.modindex-jumpbox { + border-top: 1px solid #ddd; + border-bottom: 1px solid #ddd; + margin: 1em 0 1em 0; + padding: 0.4em; +} + +div.genindex-jumpbox { + border-top: 1px solid #ddd; + border-bottom: 1px solid #ddd; + margin: 1em 0 1em 0; + padding: 0.4em; +} + +/* -- domain module index --------------------------------------------------- */ + +table.modindextable td { + padding: 2px; + border-collapse: collapse; +} + +/* -- general body styles --------------------------------------------------- */ + +div.body p, div.body dd, div.body li, div.body blockquote { + -moz-hyphens: auto; + -ms-hyphens: auto; + -webkit-hyphens: auto; + hyphens: auto; +} + +a.headerlink { + visibility: hidden; +} + +h1:hover > a.headerlink, +h2:hover > a.headerlink, +h3:hover > a.headerlink, +h4:hover > a.headerlink, +h5:hover > a.headerlink, +h6:hover > a.headerlink, +dt:hover > a.headerlink, +caption:hover > a.headerlink, +p.caption:hover > a.headerlink, +div.code-block-caption:hover > a.headerlink { + visibility: visible; +} + +div.body p.caption { + text-align: inherit; +} + +div.body td { + text-align: left; +} + +blockquote.epigraph p.attribution { + margin-left: 50%; +} + +blockquote.epigraph { + background-color: #eee; + padding: 0.5em; +} + +.first { + margin-top: 0 !important; +} + +p.rubric { + margin-top: 30px; + font-weight: bold; +} + +img.align-left, .figure.align-left, object.align-left { + clear: left; + float: left; + margin-right: 1em; +} + +img.align-right, .figure.align-right, object.align-right { +/* clear: right; */ + float: right; + margin-left: 1em; +} + +img.align-center, .figure.align-center, object.align-center { + display: block; + margin-left: auto; + margin-right: auto; +} + +.align-left { + text-align: left; +} + +.align-center { + text-align: center; +} + +.align-right { + text-align: right; +} + +/* -- sidebars -------------------------------------------------------------- */ + +div.sidebar { + margin: 1em 1em 1em 1em; + border: 1px solid #ddb; + padding: 7px 7px 0 7px; + background-color: #ffe; + width: 40%; + float: right; +} + +p.sidebar-title { + font-weight: bold; +} + +/* -- topics ---------------------------------------------------------------- */ + +div.topic { + border: 1px solid #ccc; + padding: 7px 7px 0 7px; + margin: 10px 0 10px 0; +} + +p.topic-title { + font-size: 1.1em; + font-weight: bold; + margin-top: 10px; +} + +/* -- admonitions ----------------------------------------------------------- */ + +div.admonition { + margin-top: 10px; + margin-bottom: 10px; + padding: 7px; +} + +div.admonition dt { + font-weight: bold; +} + +div.admonition dl { + margin-bottom: 0; +} + +p.admonition-title { + margin: 0px 10px 5px 0px; + font-weight: bold; +} + +div.body p.centered { + text-align: center; + margin-top: 25px; +} + +/* -- tables ---------------------------------------------------------------- */ + +table.docutils { + border: 0; + border-collapse: collapse; +} + +table caption span.caption-number { + font-style: italic; +} + +table caption span.caption-text { +} + +dl.function table.docutils th.field-name { + width: 100px; +} + +table.docutils td, table.docutils th { + padding: 1px 8px 1px 5px; + border-top: 1px solid #aaa; + border-left: 1px solid #aaa; + border-right: 1px solid #aaa; + border-bottom: 1px solid #aaa; +} + +table.docutils th { + border-bottom: 2px solid #aaa; + background-color: #f2f2f2; +} + +table.footnote td, table.footnote th { + border: 0 !important; +} + +th { + text-align: left; + padding-right: 5px; +} + +table.citation { + border-left: solid 1px gray; + margin-left: 1px; +} + +table.citation td { + border-bottom: none; +} + +/* -- figures --------------------------------------------------------------- */ + +div.figure { + margin: 0.5em; + padding: 0.5em; +} + +div.figure p.caption { + padding: 0.3em; +} + +div.figure p.caption span.caption-number { + font-style: italic; +} + +div.figure p.caption span.caption-text { +} + +/* -- field list styles ----------------------------------------------------- */ + +table.field-list td, table.field-list th { + border: 0 !important; +} + +.field-list ul { + margin: 0; + padding-left: 1em; +} + +.field-list p { + margin: 0; +} + +.field-name { + -moz-hyphens: manual; + -ms-hyphens: manual; + -webkit-hyphens: manual; + hyphens: manual; +} + +/* -- other body styles ----------------------------------------------------- */ + +ol.arabic { + list-style: decimal; +} + +ol.loweralpha { + list-style: lower-alpha; +} + +ol.upperalpha { + list-style: upper-alpha; +} + +ol.lowerroman { + list-style: lower-roman; +} + +ol.upperroman { + list-style: upper-roman; +} + +dl { + margin-bottom: 15px; +} + +dd p { + margin-top: 0px; +} + +dd ul, dd table { + margin-bottom: 10px; +} + +dd { + margin-top: 3px; + margin-bottom: 10px; + margin-left: 30px; +} + +dt:target, .highlighted { + background-color: #fbe54e; +} + +dl.glossary dt { + font-weight: bold; + font-size: 1.1em; +} + +.optional { + font-size: 1.3em; +} + +.sig-paren { + font-size: larger; +} + +.versionmodified { + font-style: italic; +} + +.system-message { + background-color: #fda; + padding: 5px; + border: 3px solid red; +} + +.footnote:target { + background-color: #ffa; +} + +.line-block { + display: block; + margin-top: 1em; + margin-bottom: 1em; +} + +.line-block .line-block { + margin-top: 0; + margin-bottom: 0; + margin-left: 1.5em; +} + +.guilabel, .menuselection { + font-family: sans-serif; +} + +.accelerator { + text-decoration: underline; +} + +.classifier { + font-style: oblique; +} + +abbr, acronym { + border-bottom: dotted 1px; + cursor: help; +} + +/* -- code displays --------------------------------------------------------- */ + +pre { + overflow: auto; + overflow-y: hidden; /* fixes display issues on Chrome browsers */ +} + +span.pre { + -moz-hyphens: none; + -ms-hyphens: none; + -webkit-hyphens: none; + hyphens: none; +} + +td.linenos pre { + padding: 5px 0px; + border: 0; + background-color: transparent; + color: #aaa; +} + +table.highlighttable { + margin-left: 0.5em; +} + +table.highlighttable td { + padding: 0 0.5em 0 0.5em; +} + +div.code-block-caption { + padding: 2px 5px; + font-size: small; +} + +div.code-block-caption code { + background-color: transparent; +} + +div.code-block-caption + div > div.highlight > pre { + margin-top: 0; +} + +div.code-block-caption span.caption-number { + padding: 0.1em 0.3em; + font-style: italic; +} + +div.code-block-caption span.caption-text { +} + +div.literal-block-wrapper { + padding: 1em 1em 0; +} + +div.literal-block-wrapper div.highlight { + margin: 0; +} + +code.descname { + background-color: transparent; + font-weight: bold; + font-size: 1.2em; +} + +code.descclassname { + background-color: transparent; +} + +code.xref, a code { + background-color: transparent; + font-weight: bold; +} + +h1 code, h2 code, h3 code, h4 code, h5 code, h6 code { + background-color: transparent; +} + +.viewcode-link { + float: right; +} + +.viewcode-back { + float: right; + font-family: sans-serif; +} + +div.viewcode-block:target { + margin: -1px -10px; + padding: 0 10px; +} + +/* -- math display ---------------------------------------------------------- */ + +img.math { + vertical-align: middle; +} + +div.body div.math p { + text-align: center; +} + +span.eqno { + float: right; +} + +span.eqno a.headerlink { + position: relative; + left: 0px; + z-index: 1; +} + +div.math:hover a.headerlink { + visibility: visible; +} + +/* -- printout stylesheet --------------------------------------------------- */ + +@media print { + div.document, + div.documentwrapper, + div.bodywrapper { + margin: 0 !important; + width: 100%; + } + + div.sphinxsidebar, + div.related, + div.footer, + #top-link { + display: none; + } +} diff --git a/doc/_templates/localtoc.html b/doc/_templates/localtoc.html new file mode 100644 index 000000000000..14fdb12a53cc --- /dev/null +++ b/doc/_templates/localtoc.html @@ -0,0 +1,14 @@ +{# + basic/localtoc.html + ~~~~~~~~~~~~~~~~~~~ + + Sphinx sidebar template: local table of contents. + + :copyright: Copyright 2007-2017 by the Sphinx team, see AUTHORS. + :license: BSD, see LICENSE for details. +#} +{%- if display_toc %} +

{{ _('On This Page') }}

+ {{ toc }} +

{{ _('Full Documentation') }}

+{%- endif %} diff --git a/doc/api.rst b/doc/api.rst new file mode 100644 index 000000000000..98df01c99edb --- /dev/null +++ b/doc/api.rst @@ -0,0 +1,1620 @@ +.. index: API + +The libxo API +============= + +This section gives details about the functions in libxo, how to call +them, and the actions they perform. + +.. index:: Handles +.. _handles: + +Handles +------- + +libxo uses "handles" to control its rendering functionality. The +handle contains state and buffered data, as well as callback functions +to process data. + +Handles give an abstraction for libxo that encapsulates the state of a +stream of output. Handles have the data type "`xo_handle_t`" and are +opaque to the caller. + +The library has a default handle that is automatically initialized. +By default, this handle will send text style output (`XO_STYLE_TEXT`) to +standard output. The xo_set_style and xo_set_flags functions can be +used to change this behavior. + +For the typical command that is generating output on standard output, +there is no need to create an explicit handle, but they are available +when needed, e.g., for daemons that generate multiple streams of +output. + +Many libxo functions take a handle as their first parameter; most that +do not use the default handle. Any function taking a handle can be +passed NULL to access the default handle. For the convenience of +callers, the libxo library includes handle-less functions that +implicitly use the default handle. + +For example, the following are equivalent:: + + xo_emit("test"); + xo_emit_h(NULL, "test"); + +Handles are created using `xo_create` and destroy using +`xo_destroy`. + +.. index:: xo_create + +xo_create +~~~~~~~~~ + +.. c:function:: xo_handle_t *xo_create (xo_style_t style, xo_xof_flags_t flags) + + The `xo_create` function allocates a new handle which can be passed + to further libxo function calls. The `xo_handle_t` structure is + opaque. + + :param xo_style_t style: Output style (XO_STYLE\_*) + :param xo_xof_flags_t flags: Flags for this handle (XOF\_*) + :return: New libxo handle + :rtype: xo_handle_t \* + + :: + + EXAMPLE: + xo_handle_t *xop = xo_create(XO_STYLE_JSON, XOF_WARN | XOF_PRETTY); + .... + xo_emit_h(xop, "testing\n"); + + See also :ref:`output-styles` and :ref:`flags`. + +.. index:: xo_create_to_file +.. index:: XOF_CLOSE_FP + +xo_create_to_file +~~~~~~~~~~~~~~~~~ + +.. c:function:: + xo_handle_t *xo_create_to_file (FILE *fp, unsigned style, unsigned flags) + + The `xo_create_to_file` function is aconvenience function is + provided for situations when output should be written to a different + file, rather than the default of standard output. + + The `XOF_CLOSE_FP` flag can be set on the returned handle to trigger a + call to fclose() for the FILE pointer when the handle is destroyed, + avoiding the need for the caller to perform this task. + + :param fp: FILE to use as base for this handle + :type fp: FILE * + :param xo_style_t style: Output style (XO_STYLE\_*) + :param xo_xof_flags_t flags: Flags for this handle (XOF\_*) + :return: New libxo handle + :rtype: xo_handle_t \* + +.. index:: xo_set_writer +.. index:: xo_write_func_t +.. index:: xo_close_func_t +.. index:: xo_flush_func_t + +xo_set_writer +~~~~~~~~~~~~~ + +.. c:function:: + void xo_set_writer (xo_handle_t *xop, void *opaque, \ + xo_write_func_t write_func, xo_close_func_t close_func, \ + xo_flush_func_t flush_func) + + The `xo_set_writer` function allows custom functions which can + tailor how libxo writes data. The `opaque` argument is recorded and + passed back to the functions, allowing the function to acquire + context information. The *write_func* function writes data to the + output stream. The *close_func* function can release this opaque + data and any other resources as needed. The *flush_func* function + is called to flush buffered data associated with the opaque object. + + :param xop: Handle to modify (or NULL for default handle) + :type xop: xo_handle_t * + :param opaque: Pointer to opaque data passed to the given functions + :type opaque: void * + :param xo_write_func_t write_func: New write function + :param xo_close_func_t close_func: New close function + :param xo_flush_func_t flush_func: New flush function + :returns: void + +.. index:: xo_get_style + +xo_get_style +~~~~~~~~~~~~ + +.. c:function:: xo_style_t xo_get_style(xo_handle_t *xop) + + Use the `xo_get_style` function to find the current output style for + a given handle. To use the default handle, pass a `NULL` handle. + + :param xop: Handle to interrogate (or NULL for default handle) + :type xop: xo_handle_t * + :returns: Output style (XO_STYLE\_*) + :rtype: xo_style_t + + :: + + EXAMPLE:: + style = xo_get_style(NULL); + +.. index:: XO_STYLE_TEXT +.. index:: XO_STYLE_XML +.. index:: XO_STYLE_JSON +.. index:: XO_STYLE_HTML + +.. _output-styles: + +Output Styles (XO_STYLE\_\*) +++++++++++++++++++++++++++++ + +The libxo functions accept a set of output styles: + +=============== ========================= + Flag Description +=============== ========================= + XO_STYLE_TEXT Traditional text output + XO_STYLE_XML XML encoded data + XO_STYLE_JSON JSON encoded data + XO_STYLE_HTML HTML encoded data +=============== ========================= + +The "XML", "JSON", and "HTML" output styles all use the UTF-8 +character encoding. "TEXT" using locale-based encoding. + +.. index:: xo_set_style + +xo_set_style +~~~~~~~~~~~~ + +.. c:function:: void xo_set_style(xo_handle_t *xop, xo_style_t style) + + The `xo_set_style` function is used to change the output style + setting for a handle. To use the default handle, pass a `NULL` + handle. + + :param xop: Handle to modify + :type xop: xo_handle_t * + :param xo_style_t style: Output style (XO_STYLE\_*) + :returns: void + + :: + + EXAMPLE: + xo_set_style(NULL, XO_STYLE_XML); + +.. index:: xo_set_style_name + +xo_set_style_name +~~~~~~~~~~~~~~~~~ + +.. c:function:: int xo_set_style_name (xo_handle_t *xop, const char *style) + + The `xo_set_style_name` function can be used to set the style based + on a name encoded as a string: The name can be any of the supported + styles: "text", "xml", "json", or "html". + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param style: Text name of the style + :type style: const char \* + :returns: zero for success, non-zero for error + :rtype: int + + :: + + EXAMPLE: + xo_set_style_name(NULL, "html"); + +.. index:: xo_set_flags + +xo_set_flags +~~~~~~~~~~~~ + +.. c:function:: void xo_set_flags(xo_handle_t *xop, xo_xof_flags_t flags) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param xo_xof_flags_t flags: Flags to add for the handle + :returns: void + + Use the `xo_set_flags` function to turn on flags for a given libxo + handle. To use the default handle, pass a `NULL` handle. + + :: + + EXAMPLE: + xo_set_flags(NULL, XOF_PRETTY | XOF_WARN); + +.. index:: Flags; XOF_* +.. index:: XOF_CLOSE_FP +.. index:: XOF_COLOR +.. index:: XOF_COLOR_ALLOWED +.. index:: XOF_DTRT +.. index:: XOF_INFO +.. index:: XOF_KEYS +.. index:: XOF_NO_ENV +.. index:: XOF_NO_HUMANIZE +.. index:: XOF_PRETTY +.. index:: XOF_UNDERSCORES +.. index:: XOF_UNITS +.. index:: XOF_WARN +.. index:: XOF_WARN_XML +.. index:: XOF_XPATH +.. index:: XOF_COLUMNS +.. index:: XOF_FLUSH + +.. _flags: + +Flags (XOF\_\*) ++++++++++++++++ + +The set of valid flags include: + +=================== ========================================= + Flag Description +=================== ========================================= + XOF_CLOSE_FP Close file pointer on `xo_destroy` + XOF_COLOR Enable color and effects in output + XOF_COLOR_ALLOWED Allow color/effect for terminal output + XOF_DTRT Enable "do the right thing" mode + XOF_INFO Display info data attributes (HTML) + XOF_KEYS Emit the key attribute (XML) + XOF_NO_ENV Do not use the :ref:`libxo-options` env var + XOF_NO_HUMANIZE Display humanization (TEXT, HTML) + XOF_PRETTY Make "pretty printed" output + XOF_UNDERSCORES Replaces hyphens with underscores + XOF_UNITS Display units (XML, HMTL) + XOF_WARN Generate warnings for broken calls + XOF_WARN_XML Generate warnings in XML on stdout + XOF_XPATH Emit XPath expressions (HTML) + XOF_COLUMNS Force xo_emit to return columns used + XOF_FLUSH Flush output after each `xo_emit` call +=================== ========================================= + +The `XOF_CLOSE_FP` flag will trigger the call of the *close_func* +(provided via `xo_set_writer`) when the handle is destroyed. + +The `XOF_COLOR` flag enables color and effects in output regardless +of output device, while the `XOF_COLOR_ALLOWED` flag allows color +and effects only if the output device is a terminal. + +The `XOF_PRETTY` flag requests "pretty printing", which will trigger +the addition of indentation and newlines to enhance the readability of +XML, JSON, and HTML output. Text output is not affected. + +The `XOF_WARN` flag requests that warnings will trigger diagnostic +output (on standard error) when the library notices errors during +operations, or with arguments to functions. Without warnings enabled, +such conditions are ignored. + +Warnings allow developers to debug their interaction with libxo. +The function `xo_failure` can used as a breakpoint for a debugger, +regardless of whether warnings are enabled. + +If the style is `XO_STYLE_HTML`, the following additional flags can be +used: + +=============== ========================================= + Flag Description +=============== ========================================= + XOF_XPATH Emit "data-xpath" attributes + XOF_INFO Emit additional info fields +=============== ========================================= + +The `XOF_XPATH` flag enables the emission of XPath expressions detailing +the hierarchy of XML elements used to encode the data field, if the +XPATH style of output were requested. + +The `XOF_INFO` flag encodes additional informational fields for HTML +output. See :ref:`field-information` for details. + +If the style is `XO_STYLE_XML`, the following additional flags can be +used: + +=============== ========================================= + Flag Description +=============== ========================================= + XOF_KEYS Flag "key" fields for XML +=============== ========================================= + +The `XOF_KEYS` flag adds "key" attribute to the XML encoding for +field definitions that use the "k" modifier. The key attribute has +the value "key":: + + xo_emit("{k:name}", item); + + XML: + truck + +.. index:: xo_clear_flags + +xo_clear_flags +++++++++++++++ + +.. c:function:: void xo_clear_flags (xo_handle_t *xop, xo_xof_flags_t flags) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param xo_xof_flags_t flags: Flags to clear for the handle + :returns: void + + Use the `xo_clear_flags` function to turn off the given flags in a + specific handle. To use the default handle, pass a `NULL` handle. + +.. index:: xo_set_options + +xo_set_options +++++++++++++++ + +.. c:function:: int xo_set_options (xo_handle_t *xop, const char *input) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param input: string containing options to set + :type input: const char * + :returns: zero for success, non-zero for error + :rtype: int + + The `xo_set_options` function accepts a comma-separated list of + output styles and modifier flags and enables them for a specific + handle. The options are identical to those listed in + :ref:`options`. To use the default handle, pass a `NULL` handle. + +.. index:: xo_destroy + +xo_destroy +++++++++++ + +.. c:function:: void xo_destroy(xo_handle_t *xop) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :returns: void + + The `xo_destroy` function releases a handle and any resources it is + using. Calling `xo_destroy` with a `NULL` handle will release any + resources associated with the default handle. + +.. index:: xo_emit + +Emitting Content (xo_emit) +-------------------------- + +The functions in this section are used to emit output. + +The "fmt" argument is a string containing field descriptors as +specified in :ref:`format-strings`. The use of a handle is optional and +`NULL` can be passed to access the internal "default" handle. See +:ref:`handles`. + +The remaining arguments to `xo_emit` and `xo_emit_h` are a set of +arguments corresponding to the fields in the format string. Care must +be taken to ensure the argument types match the fields in the format +string, since an inappropriate cast can ruin your day. The vap +argument to `xo_emit_hv` points to a variable argument list that can +be used to retrieve arguments via `va_arg`. + +.. c:function:: int xo_emit (const char *fmt, ...) + + :param fmt: The format string, followed by zero or more arguments + :returns: If XOF_COLUMNS is set, the number of columns used; otherwise the number of bytes emitted + :rtype: int + +.. c:function:: int xo_emit_h (xo_handle_t *xop, const char *fmt, ...) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param fmt: The format string, followed by zero or more arguments + :returns: If XOF_COLUMNS is set, the number of columns used; otherwise the number of bytes emitted + :rtype: int + +.. c:function:: int xo_emit_hv (xo_handle_t *xop, const char *fmt, va_list vap) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param fmt: The format string + :param va_list vap: A set of variadic arguments + :returns: If XOF_COLUMNS is set, the number of columns used; otherwise the number of bytes emitted + :rtype: int + +.. index:: xo_emit_field + +Single Field Emitting Functions (xo_emit_field) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The functions in this section can also make output, but only make a +single field at a time. These functions are intended to avoid the +scenario where one would otherwise need to compose a format +descriptors using `snprintf`. The individual parts of the format +descriptor are passed in distinctly. + +.. c:function:: int xo_emit_field (const char *rolmod, const char *contents, const char *fmt, const char *efmt, ...) + + :param rolmod: A comma-separated list of field roles and field modifiers + :type rolmod: const char * + :param contents: The "contents" portion of the field description string + :type contents: const char * + :param fmt: Content format string + :type fmt: const char * + :param efmt: Encoding format string, followed by additional arguments + :type efmt: const char * + :returns: If XOF_COLUMNS is set, the number of columns used; otherwise the number of bytes emitted + :rtype: int + + :: + + EXAMPLE:: + xo_emit_field("T", "Host name is ", NULL, NULL); + xo_emit_field("V", "host-name", NULL, NULL, host-name); + +.. c:function:: int xo_emit_field_h (xo_handle_t *xop, const char *rolmod, const char *contents, const char *fmt, const char *efmt, ...) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param rolmod: A comma-separated list of field roles and field modifiers + :type rolmod: const char * + :param contents: The "contents" portion of the field description string + :type contents: const char * + :param fmt: Content format string + :type fmt: const char * + :param efmt: Encoding format string, followed by additional arguments + :type efmt: const char * + :returns: If XOF_COLUMNS is set, the number of columns used; otherwise the number of bytes emitted + :rtype: int + +.. c:function:: int xo_emit_field_hv (xo_handle_t *xop, const char *rolmod, const char *contents, const char *fmt, const char *efmt, va_list vap) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + :param rolmod: A comma-separated list of field roles and field modifiers + :type rolmod: const char * + :param contents: The "contents" portion of the field description string + :type contents: const char * + :param fmt: Content format string + :type fmt: const char * + :param efmt: Encoding format string + :type efmt: const char * + :param va_list vap: A set of variadic arguments + :returns: If XOF_COLUMNS is set, the number of columns used; otherwise the number of bytes emitted + :rtype: int + +.. index:: xo_attr +.. _xo_attr: + +Attributes (xo_attr) +~~~~~~~~~~~~~~~~~~~~ + +The functions in this section emit an XML attribute with the given name +and value. This only affects the XML output style. + +The `name` parameter give the name of the attribute to be encoded. The +`fmt` parameter gives a printf-style format string used to format the +value of the attribute using any remaining arguments, or the vap +parameter passed to `xo_attr_hv`. + +All attributes recorded via `xo_attr` are placed on the next +container, instance, leaf, or leaf list that is emitted. + +Since attributes are only emitted in XML, their use should be limited +to meta-data and additional or redundant representations of data +already emitted in other form. + +.. c:function:: int xo_attr (const char *name, const char *fmt, ...) + + :param name: Attribute name + :type name: const char * + :param fmt: Attribute value, as variadic arguments + :type fmt: const char * + :returns: -1 for error, or the number of bytes in the formatted attribute value + :rtype: int + + :: + + EXAMPLE: + xo_attr("seconds", "%ld", (unsigned long) login_time); + struct tm *tmp = localtime(login_time); + strftime(buf, sizeof(buf), "%R", tmp); + xo_emit("Logged in at {:login-time}\n", buf); + XML: + 00:14 + + +.. c:function:: int xo_attr_h (xo_handle_t *xop, const char *name, const char *fmt, ...) + + :param xop: Handle for modify (or NULL for default handle) + :type xop: xo_handle_t \* + + The `xo_attr_h` function follows the conventions of `xo_attr` but + adds an explicit libxo handle. + +.. c:function:: int xo_attr_hv (xo_handle_t *xop, const char *name, const char *fmt, va_list vap) + + The `xo_attr_h` function follows the conventions of `xo_attr_h` + but replaced the variadic list with a variadic pointer. + +.. index:: xo_flush + +Flushing Output (xo_flush) +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. c:function:: xo_ssize_t xo_flush (void) + + :returns: -1 for error, or the number of bytes generated + :rtype: xo_ssize_t + + libxo buffers data, both for performance and consistency, but also + to allow for the proper function of various advanced features. At + various times, the caller may wish to flush any data buffered within + the library. The `xo_flush` call is used for this. + + Calling `xo_flush` also triggers the flush function associated with + the handle. For the default handle, this is equivalent to + "fflush(stdio);". + +.. c:function:: xo_ssize_t xo_flush_h (xo_handle_t *xop) + + :param xop: Handle for flush (or NULL for default handle) + :type xop: xo_handle_t \* + :returns: -1 for error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_flush_h` function follows the conventions of `xo_flush`, + but adds an explicit libxo handle. + +.. index:: xo_finish +.. index:: xo_finish_atexit +.. index:: atexit + +Finishing Output (xo_finish) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +When the program is ready to exit or close a handle, a call to +`xo_finish` or `xo_finish_h` is required. This flushes any buffered +data, closes open libxo constructs, and completes any pending +operations. + +Calling this function is vital to the proper operation of libxo, +especially for the non-TEXT output styles. + +.. c:function:: xo_ssize_t xo_finish (void) + + :returns: -1 on error, or the number of bytes flushed + :rtype: xo_ssize_t + +.. c:function:: xo_ssize_t xo_finish_h (xo_handle_t *xop) + + :param xop: Handle for finish (or NULL for default handle) + :type xop: xo_handle_t \* + :returns: -1 on error, or the number of bytes flushed + :rtype: xo_ssize_t + +.. c:function:: void xo_finish_atexit (void) + + The `xo_finish_atexit` function is suitable for use with + :manpage:`atexit(3)` to ensure that `xo_finish` is called + on the default handle when the application exits. + +.. index:: UTF-8 +.. index:: xo_open_container +.. index:: xo_close_container + +Emitting Hierarchy +------------------ + +libxo represents two types of hierarchy: containers and lists. A +container appears once under a given parent where a list consists of +instances that can appear multiple times. A container is used to hold +related fields and to give the data organization and scope. + +.. index:: YANG + +.. admonition:: YANG Terminology + + libxo uses terminology from YANG (:RFC:`7950`), the data modeling + language for NETCONF: container, list, leaf, and leaf-list. + +For XML and JSON, individual fields appear inside hierarchies which +provide context and meaning to the fields. Unfortunately, these +encoding have a basic disconnect between how lists is similar objects +are represented. + +XML encodes lists as set of sequential elements:: + + phil + pallavi + sjg + +JSON encodes lists using a single name and square brackets:: + + "user": [ "phil", "pallavi", "sjg" ] + +This means libxo needs three distinct indications of hierarchy: one +for containers of hierarchy appear only once for any specific parent, +one for lists, and one for each item in a list. + +.. index:: Containers + +Containers +~~~~~~~~~~ + +A "*container*" is an element of a hierarchy that appears only once +under any specific parent. The container has no value, but serves to +contain and organize other nodes. + +To open a container, call xo_open_container() or +xo_open_container_h(). The former uses the default handle and the +latter accepts a specific handle. To close a level, use the +xo_close_container() or xo_close_container_h() functions. + +Each open call must have a matching close call. If the XOF_WARN flag +is set and the name given does not match the name of the currently open +container, a warning will be generated. + +.. c:function:: xo_ssize_t xo_open_container (const char *name) + + :param name: Name of the container + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `name` parameter gives the name of the container, encoded in + UTF-8. Since ASCII is a proper subset of UTF-8, traditional C + strings can be used directly. + +.. c:function:: xo_ssize_t xo_open_container_h (xo_handle_t *xop, const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_open_container_h` function adds a `handle` parameter. + +.. c:function:: xo_ssize_t xo_close_container (const char *name) + + :param name: Name of the container + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + +.. c:function:: xo_ssize_t xo_close_container_h (xo_handle_t *xop, const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_close_container_h` function adds a `handle` parameter. + +Use the :index:`XOF_WARN` flag to generate a warning if the name given +on the close does not match the current open container. + +For TEXT and HTML output, containers are not rendered into output +text, though for HTML they are used to record an XPath value when the +:index:`XOF_XPATH` flag is set. + +:: + + EXAMPLE: + xo_open_container("top"); + xo_open_container("system"); + xo_emit("{:host-name/%s%s%s}", hostname, + domainname ? "." : "", domainname ?: ""); + xo_close_container("system"); + xo_close_container("top"); + TEXT: + my-host.example.org + XML: + + + my-host.example.org + + + JSON: + "top" : { + "system" : { + "host-name": "my-host.example.org" + } + } + HTML: +
my-host.example.org
+ +.. index:: xo_open_instance +.. index:: xo_close_instance +.. index:: xo_open_list +.. index:: xo_close_list + +Lists and Instances +~~~~~~~~~~~~~~~~~~~ + +A "*list*" is set of one or more instances that appear under the same +parent. The instances contain details about a specific object. One +can think of instances as objects or records. A call is needed to +open and close the list, while a distinct call is needed to open and +close each instance of the list. + +The name given to all calls must be identical, and it is strongly +suggested that the name be singular, not plural, as a matter of +style and usage expectations:: + + EXAMPLE: + xo_open_list("item"); + + for (ip = list; ip->i_title; ip++) { + xo_open_instance("item"); + xo_emit("{L:Item} '{:name/%s}':\n", ip->i_title); + xo_close_instance("item"); + } + + xo_close_list("item"); + +Getting the list and instance calls correct is critical to the proper +generation of XML and JSON data. + +Opening Lists ++++++++++++++ + +.. c:function:: xo_ssize_t xo_open_list (const char *name) + + :param name: Name of the list + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_open_list` function open a list of instances. + +.. c:function:: xo_ssize_t xo_open_list_h (xo_handle_t *xop, const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + +Closing Lists ++++++++++++++ + +.. c:function:: xo_ssize_t xo_close_list (const char *name) + + :param name: Name of the list + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_close_list` function closes a list of instances. + +.. c:function:: xo_ssize_t xo_close_list_h (xo_handle_t *xop, const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_close_container_h` function adds a `handle` parameter. + +Opening Instances ++++++++++++++++++ + +.. c:function:: xo_ssize_t xo_open_instance (const char *name) + + :param name: Name of the instance (same as the list name) + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_open_instance` function open a single instance. + +.. c:function:: xo_ssize_t xo_open_instance_h (xo_handle_t *xop, const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_open_instance_h` function adds a `handle` parameter. + +Closing Instances ++++++++++++++++++ + +.. c:function:: xo_ssize_t xo_close_instance (const char *name) + + :param name: Name of the instance + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_close_instance` function closes an open instance. + +.. c:function:: xo_ssize_t xo_close_instance_h (xo_handle_t *xop, const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_close_instance_h` function adds a `handle` parameter. + + :: + + EXAMPLE: + xo_open_list("user"); + for (i = 0; i < num_users; i++) { + xo_open_instance("user"); + xo_emit("{k:name}:{:uid/%u}:{:gid/%u}:{:home}\n", + pw[i].pw_name, pw[i].pw_uid, + pw[i].pw_gid, pw[i].pw_dir); + xo_close_instance("user"); + } + xo_close_list("user"); + TEXT: + phil:1001:1001:/home/phil + pallavi:1002:1002:/home/pallavi + XML: + + phil + 1001 + 1001 + /home/phil + + + pallavi + 1002 + 1002 + /home/pallavi + + JSON: + user: [ + { + "name": "phil", + "uid": 1001, + "gid": 1001, + "home": "/home/phil", + }, + { + "name": "pallavi", + "uid": 1002, + "gid": 1002, + "home": "/home/pallavi", + } + ] + +Markers +~~~~~~~ + +Markers are used to protect and restore the state of open hierarchy +constructs (containers, lists, or instances). While a marker is open, +no other open constructs can be closed. When a marker is closed, all +constructs open since the marker was opened will be closed. + +Markers use names which are not user-visible, allowing the caller to +choose appropriate internal names. + +In this example, the code whiffles through a list of fish, calling a +function to emit details about each fish. The marker "fish-guts" is +used to ensure that any constructs opened by the function are closed +properly:: + + EXAMPLE: + for (i = 0; fish[i]; i++) { + xo_open_instance("fish"); + xo_open_marker("fish-guts"); + dump_fish_details(i); + xo_close_marker("fish-guts"); + } + +.. c:function:: xo_ssize_t xo_open_marker(const char *name) + + :param name: Name of the instance + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_open_marker` function records the current state of open tags + in order for `xo_close_marker` to close them at some later point. + +.. c:function:: xo_ssize_t xo_open_marker_h(const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_open_marker_h` function adds a `handle` parameter. + +.. c:function:: xo_ssize_t xo_close_marker(const char *name) + + :param name: Name of the instance + :type name: const char * + :returns: -1 on error, or the number of bytes generated + :rtype: xo_ssize_t + + The `xo_close_marker` function closes any open containers, lists, or + instances as needed to return to the state recorded when + `xo_open_marker` was called with the matching name. + +.. c:function:: xo_ssize_t xo_close_marker(const char *name) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_close_marker_h` function adds a `handle` parameter. + +DTRT Mode +~~~~~~~~~ + +Some users may find tracking the names of open containers, lists, and +instances inconvenient. libxo offers a "Do The Right Thing" mode, where +libxo will track the names of open containers, lists, and instances so +the close function can be called without a name. To enable DTRT mode, +turn on the XOF_DTRT flag prior to making any other libxo output:: + + xo_set_flags(NULL, XOF_DTRT); + +.. index:: XOF_DTRT + +Each open and close function has a version with the suffix "_d", which +will close the open container, list, or instance:: + + xo_open_container_d("top"); + ... + xo_close_container_d(); + +This also works for lists and instances:: + + xo_open_list_d("item"); + for (...) { + xo_open_instance_d("item"); + xo_emit(...); + xo_close_instance_d(); + } + xo_close_list_d(); + +.. index:: XOF_WARN + +Note that the XOF_WARN flag will also cause libxo to track open +containers, lists, and instances. A warning is generated when the +name given to the close function and the name recorded do not match. + +Support Functions +----------------- + +.. index:: xo_parse_args +.. _xo_parse_args: + +Parsing Command-line Arguments (xo_parse_args) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. c:function:: int xo_parse_args (int argc, char **argv) + + :param int argc: Number of arguments + :param argv: Array of argument strings + :return: -1 on error, or the number of remaining arguments + :rtype: int + + The `xo_parse_args` function is used to process a program's + arguments. libxo-specific options are processed and removed from + the argument list so the calling application does not need to + process them. If successful, a new value for argc is returned. On + failure, a message is emitted and -1 is returned:: + + argc = xo_parse_args(argc, argv); + if (argc < 0) + exit(EXIT_FAILURE); + + Following the call to xo_parse_args, the application can process the + remaining arguments in a normal manner. See :ref:`options` for a + description of valid arguments. + +.. index:: xo_set_program + +xo_set_program +~~~~~~~~~~~~~~ + +.. c:function:: void xo_set_program (const char *name) + + :param name: Name to use as the program name + :type name: const char * + :returns: void + + The `xo_set_program` function sets the name of the program as + reported by functions like `xo_failure`, `xo_warn`, `xo_err`, etc. + The program name is initialized by `xo_parse_args`, but subsequent + calls to `xo_set_program` can override this value:: + + EXAMPLE: + xo_set_program(argv[0]); + + Note that the value is not copied, so the memory passed to + `xo_set_program` (and `xo_parse_args`) must be maintained by the + caller. + +.. index:: xo_set_version + +xo_set_version +~~~~~~~~~~~~~~ + +.. c:function:: void xo_set_version (const char *version) + + :param name: Value to use as the version string + :type name: const char * + :returns: void + + The `xo_set_version` function records a version number to be emitted + as part of the data for encoding styles (XML and JSON). This + version number is suitable for tracking changes in the content, + allowing a user of the data to discern which version of the data + model is in use. + +.. c:function:: void xo_set_version_h (xo_handle_t *xop, const char *version) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + + The `xo_set_version` function adds a `handle` parameter. + +.. index:: --libxo +.. index:: XOF_INFO +.. index:: xo_info_t + +.. _field-information: + +Field Information (xo_info_t) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +HTML data can include additional information in attributes that +begin with "data-". To enable this, three things must occur: + +First the application must build an array of xo_info_t structures, +one per tag. The array must be sorted by name, since libxo uses a +binary search to find the entry that matches names from format +instructions. + +Second, the application must inform libxo about this information using +the `xo_set_info` call:: + + typedef struct xo_info_s { + const char *xi_name; /* Name of the element */ + const char *xi_type; /* Type of field */ + const char *xi_help; /* Description of field */ + } xo_info_t; + + void xo_set_info (xo_handle_t *xop, xo_info_t *infop, int count); + +Like other libxo calls, passing `NULL` for the handle tells libxo to +use the default handle. + +If the count is -1, libxo will count the elements of infop, but there +must be an empty element at the end. More typically, the number is +known to the application:: + + xo_info_t info[] = { + { "in-stock", "number", "Number of items in stock" }, + { "name", "string", "Name of the item" }, + { "on-order", "number", "Number of items on order" }, + { "sku", "string", "Stock Keeping Unit" }, + { "sold", "number", "Number of items sold" }, + }; + int info_count = (sizeof(info) / sizeof(info[0])); + ... + xo_set_info(NULL, info, info_count); + +Third, the emission of info must be triggered with the `XOF_INFO` flag +using either the `xo_set_flags` function or the "`--libxo=info`" +command line argument. + +The type and help values, if present, are emitted as the "data-type" +and "data-help" attributes:: + +
GRO-000-533
+ +.. c:function:: void xo_set_info (xo_handle_t *xop, xo_info_t *infop, int count) + + :param xop: Handle to use (or NULL for default handle) + :type xop: xo_handle_t * + :param infop: Array of information structures + :type infop: xo_info_t * + :returns: void + +.. index:: xo_set_allocator +.. index:: xo_realloc_func_t +.. index:: xo_free_func_t + +Memory Allocation +~~~~~~~~~~~~~~~~~ + +The `xo_set_allocator` function allows libxo to be used in +environments where the standard :manpage:`realloc(3)` and +:manpage:`free(3)` functions are not appropriate. + +.. c:function:: void xo_set_allocator (xo_realloc_func_t realloc_func, xo_free_func_t free_func) + + :param xo_realloc_func_t realloc_func: Allocation function + :param xo_free_func_t free_func: Free function + + *realloc_func* should expect the same arguments as + :manpage:`realloc(3)` and return a pointer to memory following the + same convention. *free_func* will receive the same argument as + :manpage:`free(3)` and should release it, as appropriate for the + environment. + +By default, the standard :manpage:`realloc(3)` and :manpage:`free(3)` +functions are used. + +.. index:: --libxo + +.. _libxo-options: + +LIBXO_OPTIONS +~~~~~~~~~~~~~ + +The environment variable "LIBXO_OPTIONS" can be set to a subset of +libxo options, including: + +- color +- flush +- flush-line +- no-color +- no-humanize +- no-locale +- no-retain +- pretty +- retain +- underscores +- warn + +For example, warnings can be enabled by:: + + % env LIBXO_OPTIONS=warn my-app + +Since environment variables are inherited, child processes will have +the same options, which may be undesirable, making the use of the +"`--libxo`" command-line option preferable in most situations. + +.. index:: xo_warn +.. index:: xo_err +.. index:: xo_errx +.. index:: xo_message + +Errors, Warnings, and Messages +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Many programs make use of the standard library functions +:manpage:`err(3)` and :manpage:`warn(3)` to generate errors and +warnings for the user. libxo wants to pass that information via the +current output style, and provides compatible functions to allow +this:: + + void xo_warn (const char *fmt, ...); + void xo_warnx (const char *fmt, ...); + void xo_warn_c (int code, const char *fmt, ...); + void xo_warn_hc (xo_handle_t *xop, int code, + const char *fmt, ...); + void xo_err (int eval, const char *fmt, ...); + void xo_errc (int eval, int code, const char *fmt, ...); + void xo_errx (int eval, const char *fmt, ...); + +:: + + void xo_message (const char *fmt, ...); + void xo_message_c (int code, const char *fmt, ...); + void xo_message_hc (xo_handle_t *xop, int code, + const char *fmt, ...); + void xo_message_hcv (xo_handle_t *xop, int code, + const char *fmt, va_list vap); + +These functions display the program name, a colon, a formatted message +based on the arguments, and then optionally a colon and an error +message associated with either *errno* or the *code* parameter:: + + EXAMPLE: + if (open(filename, O_RDONLY) < 0) + xo_err(1, "cannot open file '%s'", filename); + +.. index:: xo_error + +xo_error +~~~~~~~~ + +.. c:function:: void xo_error (const char *fmt, ...) + + :param fmt: Format string + :type fmt: const char * + :returns: void + + The `xo_error` function can be used for generic errors that should + be reported over the handle, rather than to stderr. The `xo_error` + function behaves like `xo_err` for TEXT and HTML output styles, but + puts the error into XML or JSON elements:: + + EXAMPLE:: + xo_error("Does not %s", "compute"); + XML:: + Does not compute + JSON:: + "error": { "message": "Does not compute" } + +.. index:: xo_no_setlocale +.. index:: Locale + +xo_no_setlocale +~~~~~~~~~~~~~~~ + +.. c:function:: void xo_no_setlocale (void) + + libxo automatically initializes the locale based on setting of the + environment variables LC_CTYPE, LANG, and LC_ALL. The first of this + list of variables is used and if none of the variables, the locale + defaults to "UTF-8". The caller may wish to avoid this behavior, + and can do so by calling the `xo_no_setlocale` function. + +Emitting syslog Messages +------------------------ + +syslog is the system logging facility used throughout the unix world. +Messages are sent from commands, applications, and daemons to a +hierarchy of servers, where they are filtered, saved, and forwarded +based on configuration behaviors. + +syslog is an older protocol, originally documented only in source +code. By the time :RFC:`3164` published, variation and mutation left the +leading "" string as only common content. :RFC:`5424` defines a new +version (version 1) of syslog and introduces structured data into the +messages. Structured data is a set of name/value pairs transmitted +distinctly alongside the traditional text message, allowing filtering +on precise values instead of regular expressions. + +These name/value pairs are scoped by a two-part identifier; an +enterprise identifier names the party responsible for the message +catalog and a name identifying that message. `Enterprise IDs`_ are +defined by IANA, the Internet Assigned Numbers Authority. + +.. _Enterprise IDs: + https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers + +Use the `xo_set_syslog_enterprise_id` function to set the Enterprise +ID, as needed. + +The message name should follow the conventions in +:ref:`good-field-names`\ , as should the fields within the message:: + + /* Both of these calls are optional */ + xo_set_syslog_enterprise_id(32473); + xo_open_log("my-program", 0, LOG_DAEMON); + + /* Generate a syslog message */ + xo_syslog(LOG_ERR, "upload-failed", + "error <%d> uploading file '{:filename}' " + "as '{:target/%s:%s}'", + code, filename, protocol, remote); + + xo_syslog(LOG_INFO, "poofd-invalid-state", + "state {:current/%u} is invalid {:connection/%u}", + state, conn); + +The developer should be aware that the message name may be used in the +future to allow access to further information, including +documentation. Care should be taken to choose quality, descriptive +names. + +.. _syslog-details: + +Priority, Facility, and Flags +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The `xo_syslog`, `xo_vsyslog`, and `xo_open_log` functions +accept a set of flags which provide the priority of the message, the +source facility, and some additional features. These values are OR'd +together to create a single integer argument:: + + xo_syslog(LOG_ERR | LOG_AUTH, "login-failed", + "Login failed; user '{:user}' from host '{:address}'", + user, addr); + +These values are defined in . + +The priority value indicates the importance and potential impact of +each message: + +============= ======================================================= + Priority Description +============= ======================================================= + LOG_EMERG A panic condition, normally broadcast to all users + LOG_ALERT A condition that should be corrected immediately + LOG_CRIT Critical conditions + LOG_ERR Generic errors + LOG_WARNING Warning messages + LOG_NOTICE Non-error conditions that might need special handling + LOG_INFO Informational messages + LOG_DEBUG Developer-oriented messages +============= ======================================================= + +The facility value indicates the source of message, in fairly generic +terms: + +=============== ======================================================= + Facility Description +=============== ======================================================= + LOG_AUTH The authorization system (e.g. :manpage:`login(1)`) + LOG_AUTHPRIV As LOG_AUTH, but logged to a privileged file + LOG_CRON The cron daemon: :manpage:`cron(8)` + LOG_DAEMON System daemons, not otherwise explicitly listed + LOG_FTP The file transfer protocol daemons + LOG_KERN Messages generated by the kernel + LOG_LPR The line printer spooling system + LOG_MAIL The mail system + LOG_NEWS The network news system + LOG_SECURITY Security subsystems, such as :manpage:`ipfw(4)` + LOG_SYSLOG Messages generated internally by :manpage:`syslogd(8)` + LOG_USER Messages generated by user processes (default) + LOG_UUCP The uucp system + LOG_LOCAL0..7 Reserved for local use +=============== ======================================================= + +In addition to the values listed above, xo_open_log accepts a set of +addition flags requesting specific logging behaviors: + +============ ==================================================== + Flag Description +============ ==================================================== + LOG_CONS If syslogd fails, attempt to write to /dev/console + LOG_NDELAY Open the connection to :manpage:`syslogd(8)` immediately + LOG_PERROR Write the message also to standard error output + LOG_PID Log the process id with each message +============ ==================================================== + +.. index:: xo_syslog + +xo_syslog +~~~~~~~~~ + +.. c:function:: void xo_syslog (int pri, const char *name, const char *fmt, ...) + + :param int pri: syslog priority + :param name: Name of the syslog event + :type name: const char * + :param fmt: Format string, followed by arguments + :type fmt: const char * + :returns: void + + Use the `xo_syslog` function to generate syslog messages by calling + it with a log priority and facility, a message name, a format + string, and a set of arguments. The priority/facility argument are + discussed above, as is the message name. + + The format string follows the same conventions as `xo_emit`'s format + string, with each field being rendered as an SD-PARAM pair:: + + xo_syslog(LOG_ERR, "poofd-missing-file", + "'{:filename}' not found: {:error/%m}", filename); + + ... [poofd-missing-file@32473 filename="/etc/poofd.conf" + error="Permission denied"] '/etc/poofd.conf' not + found: Permission denied + +Support functions +~~~~~~~~~~~~~~~~~ + +.. index:: xo_vsyslog + +xo_vsyslog +++++++++++ + +.. c:function:: void xo_vsyslog (int pri, const char *name, const char *fmt, va_list vap) + + :param int pri: syslog priority + :param name: Name of the syslog event + :type name: const char * + :param fmt: Format string + :type fmt: const char * + :param va_list vap: Variadic argument list + :returns: void + + xo_vsyslog is identical in function to xo_syslog, but takes the set of + arguments using a va_list:: + + EXAMPLE: + void + my_log (const char *name, const char *fmt, ...) + { + va_list vap; + va_start(vap, fmt); + xo_vsyslog(LOG_ERR, name, fmt, vap); + va_end(vap); + } + +.. index:: xo_open_log + +xo_open_log ++++++++++++ + +.. c:function:: void xo_open_log (const char *ident, int logopt, int facility) + + :param indent: + :type indent: const char * + :param int logopt: Bit field containing logging options + :param int facility: + :returns: void + + xo_open_log functions similar to :manpage:`openlog(3)`, allowing + customization of the program name, the log facility number, and the + additional option flags described in :ref:`syslog-details`. + +.. index:: xo_close_log + +xo_close_log +++++++++++++ + +.. c:function:: void xo_close_log (void) + + The `xo_close_log` function is similar to :manpage:`closelog(3)`, + closing the log file and releasing any associated resources. + +.. index:: xo_set_logmask + +xo_set_logmask +++++++++++++++ + +.. c:function:: int xo_set_logmask (int maskpri) + + :param int maskpri: the log priority mask + :returns: The previous log priority mask + + The `xo_set_logmask` function is similar to :manpage:`setlogmask(3)`, + restricting the set of generated log event to those whose associated + bit is set in maskpri. Use `LOG_MASK(pri)` to find the appropriate bit, + or `LOG_UPTO(toppri)` to create a mask for all priorities up to and + including toppri:: + + EXAMPLE: + setlogmask(LOG_UPTO(LOG_WARN)); + +.. index:: xo_set_syslog_enterprise_id + +xo_set_syslog_enterprise_id ++++++++++++++++++++++++++++ + +.. c:function:: void xo_set_syslog_enterprise_id (unsigned short eid) + + Use the `xo_set_syslog_enterprise_id` to supply a platform- or + application-specific enterprise id. This value is used in any future + syslog messages. + + Ideally, the operating system should supply a default value via the + "kern.syslog.enterprise_id" sysctl value. Lacking that, the + application should provide a suitable value. + +Enterprise IDs are administered by IANA, the Internet Assigned Number +Authority. The complete list is EIDs on their web site:: + + https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers + +New EIDs can be requested from IANA using the following page:: + + http://pen.iana.org/pen/PenApplication.page + +Each software development organization that defines a set of syslog +messages should register their own EID and use that value in their +software to ensure that messages can be uniquely identified by the +combination of EID + message name. + +Creating Custom Encoders +------------------------ + +The number of encoding schemes in current use is staggering, with new +and distinct schemes appearing daily. While libxo provide XML, JSON, +HMTL, and text natively, there are requirements for other encodings. + +Rather than bake support for all possible encoders into libxo, the API +allows them to be defined externally. libxo can then interfaces with +these encoding modules using a simplistic API. libxo processes all +functions calls, handles state transitions, performs all formatting, +and then passes the results as operations to a customized encoding +function, which implements specific encoding logic as required. This +means your encoder doesn't need to detect errors with unbalanced +open/close operations but can rely on libxo to pass correct data. + +By making a simple API, libxo internals are not exposed, insulating the +encoder and the library from future or internal changes. + +The three elements of the API are: + +- loading +- initialization +- operations + +The following sections provide details about these topics. + +.. index:: CBOR + +libxo source contains an encoder for Concise Binary Object +Representation, aka CBOR (:RFC:`7049`), which can be used as an +example for the API for other encoders. + +Loading Encoders +~~~~~~~~~~~~~~~~ + +Encoders can be registered statically or discovered dynamically. +Applications can choose to call the `xo_encoder_register` function +to explicitly register encoders, but more typically they are built as +shared libraries, placed in the libxo/extensions directory, and loaded +based on name. libxo looks for a file with the name of the encoder +and an extension of ".enc". This can be a file or a symlink to the +shared library file that supports the encoder:: + + % ls -1 lib/libxo/extensions/*.enc + lib/libxo/extensions/cbor.enc + lib/libxo/extensions/test.enc + +Encoder Initialization +~~~~~~~~~~~~~~~~~~~~~~ + +Each encoder must export a symbol used to access the library, which +must have the following signature:: + + int xo_encoder_library_init (XO_ENCODER_INIT_ARGS); + +`XO_ENCODER_INIT_ARGS` is a macro defined in "xo_encoder.h" that defines +an argument called "arg", a pointer of the type +`xo_encoder_init_args_t`. This structure contains two fields: + +- `xei_version` is the version number of the API as implemented + within libxo. This version is currently as 1 using + `XO_ENCODER_VERSION`. This number can be checked to ensure + compatibility. The working assumption is that all versions should + be backward compatible, but each side may need to accurately know + the version supported by the other side. `xo_encoder_library_init` + can optionally check this value, and must then set it to the version + number used by the encoder, allowing libxo to detect version + differences and react accordingly. For example, if version 2 adds + new operations, then libxo will know that an encoding library that + set `xei_version` to 1 cannot be expected to handle those new + operations. + +- xei_handler must be set to a pointer to a function of type + `xo_encoder_func_t`, as defined in "xo_encoder.h". This function + takes a set of parameters: + - xop is a pointer to the opaque `xo_handle_t` structure + - op is an integer representing the current operation + - name is a string whose meaning differs by operation + - value is a string whose meaning differs by operation + - private is an opaque structure provided by the encoder + +Additional arguments may be added in the future, so handler functions +should use the `XO_ENCODER_HANDLER_ARGS` macro. An appropriate +"extern" declaration is provided to help catch errors. + +Once the encoder initialization function has completed processing, it +should return zero to indicate that no error has occurred. A non-zero +return code will cause the handle initialization to fail. + +Operations +~~~~~~~~~~ + +The encoder API defines a set of operations representing the +processing model of libxo. Content is formatted within libxo, and +callbacks are made to the encoder's handler function when data is +ready to be processed: + +======================= ======================================= + Operation Meaning (Base function) +======================= ======================================= + XO_OP_CREATE Called when the handle is created + XO_OP_OPEN_CONTAINER Container opened (xo_open_container) + XO_OP_CLOSE_CONTAINER Container closed (xo_close_container) + XO_OP_OPEN_LIST List opened (xo_open_list) + XO_OP_CLOSE_LIST List closed (xo_close_list) + XO_OP_OPEN_LEAF_LIST Leaf list opened (xo_open_leaf_list) + XO_OP_CLOSE_LEAF_LIST Leaf list closed (xo_close_leaf_list) + XO_OP_OPEN_INSTANCE Instance opened (xo_open_instance) + XO_OP_CLOSE_INSTANCE Instance closed (xo_close_instance) + XO_OP_STRING Field with Quoted UTF-8 string + XO_OP_CONTENT Field with content + XO_OP_FINISH Finish any pending output + XO_OP_FLUSH Flush any buffered output + XO_OP_DESTROY Clean up resources + XO_OP_ATTRIBUTE An attribute name/value pair + XO_OP_VERSION A version string +======================= ======================================= + +For all the open and close operations, the name parameter holds the +name of the construct. For string, content, and attribute operations, +the name parameter is the name of the field and the value parameter is +the value. "string" are differentiated from "content" to allow differing +treatment of true, false, null, and numbers from real strings, though +content values are formatted as strings before the handler is called. +For version operations, the value parameter contains the version. + +All strings are encoded in UTF-8. diff --git a/doc/conf.py b/doc/conf.py new file mode 100644 index 000000000000..2d4d8d8b2951 --- /dev/null +++ b/doc/conf.py @@ -0,0 +1,178 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- +# +# JuniperStory documentation build configuration file, created by +# sphinx-quickstart on Tue Oct 10 10:18:55 2017. +# +# This file is execfile()d with the current directory set to its +# containing dir. +# +# Note that not all possible configuration values are present in this +# autogenerated file. +# +# All configuration values have a default; values that are commented out +# serve to show the default. + +# If extensions (or modules to document with autodoc) are in another directory, +# add these directories to sys.path here. If the directory is relative to the +# documentation root, use os.path.abspath to make it absolute, like shown here. +# +# import os +# import sys +# sys.path.insert(0, os.path.abspath('.')) + + +# -- General configuration ------------------------------------------------ + +# If your documentation needs a minimal Sphinx version, state it here. +# +# needs_sphinx = '1.0' + +# Add any Sphinx extension module names here, as strings. They can be +# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom +# ones. +extensions = [] + +# Add any paths that contain templates here, relative to this directory. +templates_path = ['_templates'] + +# The suffix(es) of source filenames. +# You can specify multiple suffix as a list of string: +# +# source_suffix = ['.rst', '.md'] +source_suffix = '.rst' + +# The master toctree document. +master_doc = 'index' + +# General information about the project. +project = 'libxo' +copyright = '2017, Juniper Networks' +author = 'Phil Shafer' +default_role = 'code' +primary_domain = 'c' +smart_quotes = False + +# The version info for the project you're documenting, acts as replacement for +# |version| and |release|, also used in various other places throughout the +# built documents. +# +# The short X.Y version. +version = '0.8.4' +# The full version, including alpha/beta/rc tags. +release = '0.8.4' + +# The language for content autogenerated by Sphinx. Refer to documentation +# for a list of supported languages. +# +# This is also used if you do content translation via gettext catalogs. +# Usually you set "language" from the command line for these cases. +language = None + +# List of patterns, relative to source directory, that match files and +# directories to ignore when looking for source files. +# This patterns also effect to html_static_path and html_extra_path +exclude_patterns = [] + +# The name of the Pygments (syntax highlighting) style to use. +pygments_style = 'sphinx' + +# If true, `todo` and `todoList` produce output, else they produce nothing. +todo_include_todos = False + + +# -- Options for HTML output ---------------------------------------------- + +# The theme to use for HTML and HTML Help pages. See the documentation for +# a list of builtin themes. +# +html_theme = 'sphinxdoc' + +# Theme options are theme-specific and customize the look and feel of a theme +# further. For a list of options available for each theme, see the +# documentation. +# +# html_theme_options = {} +html_theme_options = { + "sidebarwidth": 320, +} + +# Add any paths that contain custom static files (such as style sheets) here, +# relative to this directory. They are copied after the builtin static files, +# so a file named "default.css" will overwrite the builtin "default.css". +html_static_path = ['_static'] + +# Custom sidebar templates, must be a dictionary that maps document names +# to template names. +# +# This is required for the alabaster theme +# refs: http://alabaster.readthedocs.io/en/latest/installation.html#sidebars +alabaster_html_sidebars = { + '**': [ + 'about.html', + 'navigation.html', + 'relations.html', # needs 'show_related': True theme option to display + 'searchbox.html', + 'donate.html', + ] +} + + +# -- Options for HTMLHelp output ------------------------------------------ + +# Output file base name for HTML help builder. +htmlhelp_basename = 'libxo-manual' + + +# -- Options for LaTeX output --------------------------------------------- + +latex_elements = { + # The paper size ('letterpaper' or 'a4paper'). + # + # 'papersize': 'letterpaper', + + # The font size ('10pt', '11pt' or '12pt'). + # + # 'pointsize': '10pt', + + # Additional stuff for the LaTeX preamble. + # + # 'preamble': '', + + # Latex figure (float) alignment + # + # 'figure_align': 'htbp', +} + +# Grouping the document tree into LaTeX files. List of tuples +# (source start file, target name, title, +# author, documentclass [howto, manual, or own class]). +latex_documents = [ + (master_doc, 'libxo.tex', 'libxo Documentation', + 'Phil Shafer', 'manual'), +] + + +# -- Options for manual page output --------------------------------------- + +# One entry per manual page. List of tuples +# (source start file, name, description, authors, manual section). +man_pages = [ + (master_doc, 'libxo', 'libxo Documentation', + [author], 1) +] + + +# -- Options for Texinfo output ------------------------------------------- + +# Grouping the document tree into Texinfo files. List of tuples +# (source start file, target name, title, author, +# dir menu entry, description, category) +texinfo_documents = [ + (master_doc, 'libxo', 'libxo Documentation', + author, 'libxo', 'A Library for Generating Text, XML, JSON, and HTML Output', + 'Miscellaneous'), +] + + + diff --git a/doc/example.rst b/doc/example.rst new file mode 100644 index 000000000000..2975ddeb1b59 --- /dev/null +++ b/doc/example.rst @@ -0,0 +1,694 @@ + +Examples +======== + +Unit Test +--------- + +Here is one of the unit tests as an example:: + + int + main (int argc, char **argv) + { + static char base_grocery[] = "GRO"; + static char base_hardware[] = "HRD"; + struct item { + const char *i_title; + int i_sold; + int i_instock; + int i_onorder; + const char *i_sku_base; + int i_sku_num; + }; + struct item list[] = { + { "gum", 1412, 54, 10, base_grocery, 415 }, + { "rope", 85, 4, 2, base_hardware, 212 }, + { "ladder", 0, 2, 1, base_hardware, 517 }, + { "bolt", 4123, 144, 42, base_hardware, 632 }, + { "water", 17, 14, 2, base_grocery, 2331 }, + { NULL, 0, 0, 0, NULL, 0 } + }; + struct item list2[] = { + { "fish", 1321, 45, 1, base_grocery, 533 }, + }; + struct item *ip; + xo_info_t info[] = { + { "in-stock", "number", "Number of items in stock" }, + { "name", "string", "Name of the item" }, + { "on-order", "number", "Number of items on order" }, + { "sku", "string", "Stock Keeping Unit" }, + { "sold", "number", "Number of items sold" }, + { NULL, NULL, NULL }, + }; + int info_count = (sizeof(info) / sizeof(info[0])) - 1; + + argc = xo_parse_args(argc, argv); + if (argc < 0) + exit(EXIT_FAILURE); + + xo_set_info(NULL, info, info_count); + + xo_open_container_h(NULL, "top"); + + xo_open_container("data"); + xo_open_list("item"); + + for (ip = list; ip->i_title; ip++) { + xo_open_instance("item"); + + xo_emit("{L:Item} '{k:name/%s}':\n", ip->i_title); + xo_emit("{P: }{L:Total sold}: {n:sold/%u%s}\n", + ip->i_sold, ip->i_sold ? ".0" : ""); + xo_emit("{P: }{Lwc:In stock}{:in-stock/%u}\n", + ip->i_instock); + xo_emit("{P: }{Lwc:On order}{:on-order/%u}\n", + ip->i_onorder); + xo_emit("{P: }{L:SKU}: {q:sku/%s-000-%u}\n", + ip->i_sku_base, ip->i_sku_num); + + xo_close_instance("item"); + } + + xo_close_list("item"); + xo_close_container("data"); + + xo_open_container("data"); + xo_open_list("item"); + + for (ip = list2; ip->i_title; ip++) { + xo_open_instance("item"); + + xo_emit("{L:Item} '{:name/%s}':\n", ip->i_title); + xo_emit("{P: }{L:Total sold}: {n:sold/%u%s}\n", + ip->i_sold, ip->i_sold ? ".0" : ""); + xo_emit("{P: }{Lwc:In stock}{:in-stock/%u}\n", + ip->i_instock); + xo_emit("{P: }{Lwc:On order}{:on-order/%u}\n", + ip->i_onorder); + xo_emit("{P: }{L:SKU}: {q:sku/%s-000-%u}\n", + ip->i_sku_base, ip->i_sku_num); + + xo_close_instance("item"); + } + + xo_close_list("item"); + xo_close_container("data"); + + xo_close_container_h(NULL, "top"); + + return 0; + } + +Text output:: + + % ./testxo --libxo text + Item 'gum': + Total sold: 1412.0 + In stock: 54 + On order: 10 + SKU: GRO-000-415 + Item 'rope': + Total sold: 85.0 + In stock: 4 + On order: 2 + SKU: HRD-000-212 + Item 'ladder': + Total sold: 0 + In stock: 2 + On order: 1 + SKU: HRD-000-517 + Item 'bolt': + Total sold: 4123.0 + In stock: 144 + On order: 42 + SKU: HRD-000-632 + Item 'water': + Total sold: 17.0 + In stock: 14 + On order: 2 + SKU: GRO-000-2331 + Item 'fish': + Total sold: 1321.0 + In stock: 45 + On order: 1 + SKU: GRO-000-533 + +JSON output:: + + % ./testxo --libxo json,pretty + "top": { + "data": { + "item": [ + { + "name": "gum", + "sold": 1412.0, + "in-stock": 54, + "on-order": 10, + "sku": "GRO-000-415" + }, + { + "name": "rope", + "sold": 85.0, + "in-stock": 4, + "on-order": 2, + "sku": "HRD-000-212" + }, + { + "name": "ladder", + "sold": 0, + "in-stock": 2, + "on-order": 1, + "sku": "HRD-000-517" + }, + { + "name": "bolt", + "sold": 4123.0, + "in-stock": 144, + "on-order": 42, + "sku": "HRD-000-632" + }, + { + "name": "water", + "sold": 17.0, + "in-stock": 14, + "on-order": 2, + "sku": "GRO-000-2331" + } + ] + }, + "data": { + "item": [ + { + "name": "fish", + "sold": 1321.0, + "in-stock": 45, + "on-order": 1, + "sku": "GRO-000-533" + } + ] + } + } + +XML output:: + + % ./testxo --libxo pretty,xml + + + + gum + 1412.0 + 54 + 10 + GRO-000-415 + + + rope + 85.0 + 4 + 2 + HRD-000-212 + + + ladder + 0 + 2 + 1 + HRD-000-517 + + + bolt + 4123.0 + 144 + 42 + HRD-000-632 + + + water + 17.0 + 14 + 2 + GRO-000-2331 + + + + + fish + 1321.0 + 45 + 1 + GRO-000-533 + + + + +HMTL output:: + + % ./testxo --libxo pretty,html +
+
Item
+
'
+
gum
+
':
+
+
+
+
Total sold
+
:
+
1412.0
+
+
+
+
In stock
+
:
+
+
54
+
+
+
+
On order
+
:
+
+
10
+
+
+
+
SKU
+
:
+
GRO-000-415
+
+
+
Item
+
'
+
rope
+
':
+
+
+
+
Total sold
+
:
+
85.0
+
+
+
+
In stock
+
:
+
+
4
+
+
+
+
On order
+
:
+
+
2
+
+
+
+
SKU
+
:
+
HRD-000-212
+
+
+
Item
+
'
+
ladder
+
':
+
+
+
+
Total sold
+
:
+
0
+
+
+
+
In stock
+
:
+
+
2
+
+
+
+
On order
+
:
+
+
1
+
+
+
+
SKU
+
:
+
HRD-000-517
+
+
+
Item
+
'
+
bolt
+
':
+
+
+
+
Total sold
+
:
+
4123.0
+
+
+
+
In stock
+
:
+
+
144
+
+
+
+
On order
+
:
+
+
42
+
+
+
+
SKU
+
:
+
HRD-000-632
+
+
+
Item
+
'
+
water
+
':
+
+
+
+
Total sold
+
:
+
17.0
+
+
+
+
In stock
+
:
+
+
14
+
+
+
+
On order
+
:
+
+
2
+
+
+
+
SKU
+
:
+
GRO-000-2331
+
+
+
Item
+
'
+
fish
+
':
+
+
+
+
Total sold
+
:
+
1321.0
+
+
+
+
In stock
+
:
+
+
45
+
+
+
+
On order
+
:
+
+
1
+
+
+
+
SKU
+
:
+
GRO-000-533
+
+ +HTML output with xpath and info flags:: + + % ./testxo --libxo pretty,html,xpath,info +
+
Item
+
'
+
gum
+
':
+
+
+
+
Total sold
+
:
+
1412.0
+
+
+
+
In stock
+
:
+
+
54
+
+
+
+
On order
+
:
+
+
10
+
+
+
+
SKU
+
:
+
GRO-000-415
+
+
+
Item
+
'
+
rope
+
':
+
+
+
+
Total sold
+
:
+
85.0
+
+
+
+
In stock
+
:
+
+
4
+
+
+
+
On order
+
:
+
+
2
+
+
+
+
SKU
+
:
+
HRD-000-212
+
+
+
Item
+
'
+
ladder
+
':
+
+
+
+
Total sold
+
:
+
0
+
+
+
+
In stock
+
:
+
+
2
+
+
+
+
On order
+
:
+
+
1
+
+
+
+
SKU
+
:
+
HRD-000-517
+
+
+
Item
+
'
+
bolt
+
':
+
+
+
+
Total sold
+
:
+
4123.0
+
+
+
+
In stock
+
:
+
+
144
+
+
+
+
On order
+
:
+
+
42
+
+
+
+
SKU
+
:
+
HRD-000-632
+
+
+
Item
+
'
+
water
+
':
+
+
+
+
Total sold
+
:
+
17.0
+
+
+
+
In stock
+
:
+
+
14
+
+
+
+
On order
+
:
+
+
2
+
+
+
+
SKU
+
:
+
GRO-000-2331
+
+
+
Item
+
'
+
fish
+
':
+
+
+
+
Total sold
+
:
+
1321.0
+
+
+
+
In stock
+
:
+
+
45
+
+
+
+
On order
+
:
+
+
1
+
+
+
+
SKU
+
:
+
GRO-000-533
+
diff --git a/doc/faq.rst b/doc/faq.rst new file mode 100644 index 000000000000..8b6b4948daea --- /dev/null +++ b/doc/faq.rst @@ -0,0 +1,209 @@ + +FAQs +==== + +This section contains the set of questions that users typically ask, +along with answers that might be helpful. + +General +------- + +Can you share the history of libxo? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +In 2001, we added an XML API to the JUNOS operating system, which is +built on top of FreeBSD_. Eventually this API became standardized as +the NETCONF API (:RFC:`6241`). As part of this effort, we modified many +FreeBSD utilities to emit XML, typically via a "-X" switch. The +results were mixed. The cost of maintaining this code, updating it, +and carrying it were non-trivial, and contributed to our expense (and +the associated delay) with upgrading the version of FreeBSD on which +each release of JUNOS is based. + +.. _FreeBSD: https://www.freebsd.org + +A recent (2014) effort within JUNOS aims at removing our modifications +to the underlying FreeBSD code as a means of reducing the expense and +delay in tracking HEAD. JUNOS is structured to have system components +generate XML that is rendered by the CLI (think: login shell) into +human-readable text. This allows the API to use the same plumbing as +the CLI, and ensures that all components emit XML, and that it is +emitted with knowledge of the consumer of that XML, yielding an API +that have no incremental cost or feature delay. + +libxo is an effort to mix the best aspects of the JUNOS strategy into +FreeBSD in a seemless way, allowing commands to make printf-like +output calls with a single code path. + +Did the complex semantics of format strings evolve over time? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The history is both long and short: libxo's functionality is based +on what JUNOS does in a data modeling language called ODL (output +definition language). In JUNOS, all subcomponents generate XML, +which is feed to the CLI, where data from the ODL files tell is +how to render that XML into text. ODL might had a set of tags +like:: + + tag docsis-state { + help "State of the DOCSIS interface"; + type string; + } + + tag docsis-mode { + help "DOCSIS mode (2.0/3.0) of the DOCSIS interface"; + type string; + } + + tag docsis-upstream-speed { + help "Operational upstream speed of the interface"; + type string; + } + + tag downstream-scanning { + help "Result of scanning in downstream direction"; + type string; + } + + tag ranging { + help "Result of ranging action"; + type string; + } + + tag signal-to-noise-ratio { + help "Signal to noise ratio for all channels"; + type string; + } + + tag power { + help "Operational power of the signal on all channels"; + type string; + } + + format docsis-status-format { + picture " + State : @, Mode: @, Upstream speed: @ + Downstream scanning: @, Ranging: @ + Signal to noise ratio: @ + Power: @ + "; + line { + field docsis-state; + field docsis-mode; + field docsis-upstream-speed; + field downstream-scanning; + field ranging; + field signal-to-noise-ratio; + field power; + } + } + +These tag definitions are compiled into field definitions +that are triggered when matching XML elements are seen. ODL +also supports other means of defining output. + +The roles and modifiers describe these details. + +In moving these ideas to bsd, two things had to happen: the +formatting had to happen at the source since BSD won't have +a JUNOS-like CLI to do the rendering, and we can't depend on +external data models like ODL, which was seen as too hard a +sell to the BSD community. + +The results were that the xo_emit strings are used to encode the +roles, modifiers, names, and formats. They are dense and a bit +cryptic, but not so unlike printf format strings that developers will +be lost. + +libxo is a new implementation of these ideas and is distinct from +the previous implementation in JUNOS. + +.. index:: XOF_UNDERSCORES + +.. _good-field-names: + +What makes a good field name? +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +To make useful, consistent field names, follow these guidelines: + +Use lower case, even for TLAs + Lower case is more civilized. Even TLAs should be lower case + to avoid scenarios where the differences between "XPath" and + "Xpath" drive your users crazy. Using "xpath" is simpler and better. + +Use hyphens, not underscores + Use of hyphens is traditional in XML, and the XOF_UNDERSCORES + flag can be used to generate underscores in JSON, if desired. + But the raw field name should use hyphens. + +Use full words + Don't abbreviate especially when the abbreviation is not obvious or + not widely used. Use "data-size", not "dsz" or "dsize". Use + "interface" instead of "ifname", "if-name", "iface", "if", or "intf". + +Use - + Using the form - or -- helps in + making consistent, useful names, avoiding the situation where one app + uses "sent-packet" and another "packets-sent" and another + "packets-we-have-sent". The can be dropped when it is + obvious, as can obvious words in the classification. + Use "receive-after-window-packets" instead of + "received-packets-of-data-after-window". + +Reuse existing field names + Nothing's worse than writing expressions like:: + + if ($src1/process[pid == $pid]/name == + $src2/proc-table/proc-list + /prc-entry[prcss-id == $pid]/proc-name) { + ... + } + + Find someone else who is expressing similar data and follow their + fields and hierarchy. Remember the quote is not "Consistency is the + hobgoblin of little minds", but "A *foolish* consistency is the + hobgoblin of little minds". Consistency rocks! + +Use containment as scoping + In the previous example, all the names are prefixed with "proc-", + which is redundant given that they are nested under the process table. + +Think about your users + Have empathy for your users, choosing clear and useful fields that + contain clear and useful data. You may need to augment the display + content with xo_attr() calls (:ref:`xo_attr`) or "{e:}" + fields (:ref:`encoding-modifier`) to make the data useful. + +Don't use an arbitrary number postfix + What does "errors2" mean? No one will know. "errors-after-restart" + would be a better choice. Think of your users, and think of the + future. If you make "errors2", the next guy will happily make + "errors3" and before you know it, someone will be asking what's the + difference between errors37 and errors63. + +Be consistent, uniform, unsurprising, and predictable + Think of your field vocabulary as an API. You want it useful, + expressive, meaningful, direct, and obvious. You want the client + application's programmer to move between without the need to + understand a variety of opinions on how fields are named. They + should see the system as a single cohesive whole, not a sack of + cats. + +Field names constitute the means by which client programmers interact +with our system. By choosing wise names now, you are making their +lives better. + +After using `xolint` to find errors in your field descriptors, use +"`xolint -V`" to spell check your field names and to help you detect +different names for the same data. "dropped-short" and +"dropped-too-short" are both reasonable names, but using them both +will lead users to ask the difference between the two fields. If +there is no difference, use only one of the field names. If there is +a difference, change the names to make that difference more obvious. + +.. ignore for now, since we want can't have generated content + What does this message mean? + ---------------------------- + + !!include-file xolint.txt diff --git a/doc/field-formatting.rst b/doc/field-formatting.rst new file mode 100644 index 000000000000..2e2bd75dd1ca --- /dev/null +++ b/doc/field-formatting.rst @@ -0,0 +1,370 @@ + +.. index:: Field Formatting + +Field Formatting +---------------- + +The field format is similar to the format string for printf(3). Its +use varies based on the role of the field, but generally is used to +format the field's contents. + +If the format string is not provided for a value field, it defaults to +"%s". + +Note a field definition can contain zero or more printf-style +'directives', which are sequences that start with a '%' and end with +one of following characters: "diouxXDOUeEfFgGaAcCsSp". Each directive +is matched by one of more arguments to the xo_emit function. + +The format string has the form:: + + '%' format-modifier * format-character + +The format-modifier can be: + +- a '#' character, indicating the output value should be prefixed + with '0x', typically to indicate a base 16 (hex) value. +- a minus sign ('-'), indicating the output value should be padded on + the right instead of the left. +- a leading zero ('0') indicating the output value should be padded on the + left with zeroes instead of spaces (' '). +- one or more digits ('0' - '9') indicating the minimum width of the + argument. If the width in columns of the output value is less than + the minimum width, the value will be padded to reach the minimum. +- a period followed by one or more digits indicating the maximum + number of bytes which will be examined for a string argument, or the maximum + width for a non-string argument. When handling ASCII strings this + functions as the field width but for multi-byte characters, a single + character may be composed of multiple bytes. + xo_emit will never dereference memory beyond the given number of bytes. +- a second period followed by one or more digits indicating the maximum + width for a string argument. This modifier cannot be given for non-string + arguments. +- one or more 'h' characters, indicating shorter input data. +- one or more 'l' characters, indicating longer input data. +- a 'z' character, indicating a 'size_t' argument. +- a 't' character, indicating a 'ptrdiff_t' argument. +- a ' ' character, indicating a space should be emitted before + positive numbers. +- a '+' character, indicating sign should emitted before any number. + +Note that 'q', 'D', 'O', and 'U' are considered deprecated and will be +removed eventually. + +The format character is described in the following table: + +===== ================= ====================== + Ltr Argument Type Format +===== ================= ====================== + d int base 10 (decimal) + i int base 10 (decimal) + o int base 8 (octal) + u unsigned base 10 (decimal) + x unsigned base 16 (hex) + X unsigned long base 16 (hex) + D long base 10 (decimal) + O unsigned long base 8 (octal) + U unsigned long base 10 (decimal) + e double [-]d.ddde+-dd + E double [-]d.dddE+-dd + f double [-]ddd.ddd + F double [-]ddd.ddd + g double as 'e' or 'f' + G double as 'E' or 'F' + a double [-]0xh.hhhp[+-]d + A double [-]0Xh.hhhp[+-]d + c unsigned char a character + C wint_t a character + s char \* a UTF-8 string + S wchar_t \* a unicode/WCS string + p void \* '%#lx' +===== ================= ====================== + +The 'h' and 'l' modifiers affect the size and treatment of the +argument: + +===== ============= ==================== + Mod d, i o, u, x, X +===== ============= ==================== + hh signed char unsigned char + h short unsigned short + l long unsigned long + ll long long unsigned long long + j intmax_t uintmax_t + t ptrdiff_t ptrdiff_t + z size_t size_t + q quad_t u_quad_t +===== ============= ==================== + +.. index:: UTF-8 +.. index:: Locale + +.. _utf-8: + +UTF-8 and Locale Strings +~~~~~~~~~~~~~~~~~~~~~~~~ + +For strings, the 'h' and 'l' modifiers affect the interpretation of +the bytes pointed to argument. The default '%s' string is a 'char \*' +pointer to a string encoded as UTF-8. Since UTF-8 is compatible with +ASCII data, a normal 7-bit ASCII string can be used. '%ls' expects a +'wchar_t \*' pointer to a wide-character string, encoded as a 32-bit +Unicode values. '%hs' expects a 'char \*' pointer to a multi-byte +string encoded with the current locale, as given by the LC_CTYPE, +LANG, or LC_ALL environment varibles. The first of this list of +variables is used and if none of the variables are set, the locale +defaults to "UTF-8". + +libxo will convert these arguments as needed to either UTF-8 (for XML, +JSON, and HTML styles) or locale-based strings for display in text +style:: + + xo_emit("All strings are utf-8 content {:tag/%ls}", + L"except for wide strings"); + +======== ================== =============================== + Format Argument Type Argument Contents +======== ================== =============================== + %s const char \* UTF-8 string + %S const char \* UTF-8 string (alias for '%ls') + %ls const wchar_t \* Wide character UNICODE string + %hs const char * locale-based string +======== ================== =============================== + +.. admonition:: "Long", not "locale" + + The "*l*" in "%ls" is for "*long*", following the convention of "%ld". + It is not "*locale*", a common mis-mnemonic. "%S" is equivalent to + "%ls". + +For example, the following function is passed a locale-base name, a +hat size, and a time value. The hat size is formatted in a UTF-8 +(ASCII) string, and the time value is formatted into a wchar_t +string:: + + void print_order (const char *name, int size, + struct tm *timep) { + char buf[32]; + const char *size_val = "unknown"; + + if (size > 0) + snprintf(buf, sizeof(buf), "%d", size); + size_val = buf; + } + + wchar_t when[32]; + wcsftime(when, sizeof(when), L"%d%b%y", timep); + + xo_emit("The hat for {:name/%hs} is {:size/%s}.\n", + name, size_val); + xo_emit("It was ordered on {:order-time/%ls}.\n", + when); + } + +It is important to note that xo_emit will perform the conversion +required to make appropriate output. Text style output uses the +current locale (as described above), while XML, JSON, and HTML use +UTF-8. + +UTF-8 and locale-encoded strings can use multiple bytes to encode one +column of data. The traditional "precision'" (aka "max-width") value +for "%s" printf formatting becomes overloaded since it specifies both +the number of bytes that can be safely referenced and the maximum +number of columns to emit. xo_emit uses the precision as the former, +and adds a third value for specifying the maximum number of columns. + +In this example, the name field is printed with a minimum of 3 columns +and a maximum of 6. Up to ten bytes of data at the location given by +'name' are in used in filling those columns:: + + xo_emit("{:name/%3.10.6s}", name); + +Characters Outside of Field Definitions +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Characters in the format string that are not part of a field +definition are copied to the output for the TEXT style, and are +ignored for the JSON and XML styles. For HTML, these characters are +placed in a
with class "text":: + + EXAMPLE: + xo_emit("The hat is {:size/%s}.\n", size_val); + TEXT: + The hat is extra small. + XML: + extra small + JSON: + "size": "extra small" + HTML: +
The hat is
+
extra small
+
.
+ +.. index:: errno + +"%m" Is Supported +~~~~~~~~~~~~~~~~~ + +libxo supports the '%m' directive, which formats the error message +associated with the current value of "errno". It is the equivalent +of "%s" with the argument strerror(errno):: + + xo_emit("{:filename} cannot be opened: {:error/%m}", filename); + xo_emit("{:filename} cannot be opened: {:error/%s}", + filename, strerror(errno)); + +"%n" Is Not Supported +~~~~~~~~~~~~~~~~~~~~~ + +libxo does not support the '%n' directive. It's a bad idea and we +just don't do it. + +The Encoding Format (eformat) +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The "eformat" string is the format string used when encoding the field +for JSON and XML. If not provided, it defaults to the primary format +with any minimum width removed. If the primary is not given, both +default to "%s". + +Content Strings +~~~~~~~~~~~~~~~ + +For padding and labels, the content string is considered the content, +unless a format is given. + +.. index:: printf-like + +Argument Validation +~~~~~~~~~~~~~~~~~~~ + +Many compilers and tool chains support validation of printf-like +arguments. When the format string fails to match the argument list, +a warning is generated. This is a valuable feature and while the +formatting strings for libxo differ considerably from printf, many of +these checks can still provide build-time protection against bugs. + +libxo provide variants of functions that provide this ability, if the +"--enable-printflike" option is passed to the "configure" script. +These functions use the "_p" suffix, like "xo_emit_p()", +xo_emit_hp()", etc. + +The following are features of libxo formatting strings that are +incompatible with printf-like testing: + +- implicit formats, where "{:tag}" has an implicit "%s"; +- the "max" parameter for strings, where "{:tag/%4.10.6s}" means up to + ten bytes of data can be inspected to fill a minimum of 4 columns and + a maximum of 6; +- percent signs in strings, where "{:filled}%" makes a single, + trailing percent sign; +- the "l" and "h" modifiers for strings, where "{:tag/%hs}" means + locale-based string and "{:tag/%ls}" means a wide character string; +- distinct encoding formats, where "{:tag/#%s/%s}" means the display + styles (text and HTML) will use "#%s" where other styles use "%s"; + +If none of these features are in use by your code, then using the "_p" +variants might be wise: + +================== ======================== + Function printf-like Equivalent +================== ======================== + xo_emit_hv xo_emit_hvp + xo_emit_h xo_emit_hp + xo_emit xo_emit_p + xo_emit_warn_hcv xo_emit_warn_hcvp + xo_emit_warn_hc xo_emit_warn_hcp + xo_emit_warn_c xo_emit_warn_cp + xo_emit_warn xo_emit_warn_p + xo_emit_warnx xo_emit_warnx_p + xo_emit_err xo_emit_err_p + xo_emit_errx xo_emit_errx_p + xo_emit_errc xo_emit_errc_p +================== ======================== + +.. index:: performance +.. index:: XOEF_RETAIN + +.. _retain: + +Retaining Parsed Format Information +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +libxo can retain the parsed internal information related to the given +format string, allowing subsequent xo_emit calls, the retained +information is used, avoiding repetitive parsing of the format string:: + + SYNTAX: + int xo_emit_f(xo_emit_flags_t flags, const char fmt, ...); + EXAMPLE: + xo_emit_f(XOEF_RETAIN, "{:some/%02d}{:thing/%-6s}{:fancy}\n", + some, thing, fancy); + +To retain parsed format information, use the XOEF_RETAIN flag to the +xo_emit_f() function. A complete set of xo_emit_f functions exist to +match all the xo_emit function signatures (with handles, varadic +argument, and printf-like flags): + +================== ======================== + Function Flags Equivalent +================== ======================== + xo_emit_hv xo_emit_hvf + xo_emit_h xo_emit_hf + xo_emit xo_emit_f + xo_emit_hvp xo_emit_hvfp + xo_emit_hp xo_emit_hfp + xo_emit_p xo_emit_fp +================== ======================== + +The format string must be immutable across multiple calls to xo_emit_f(), +since the library retains the string. Typically this is done by using +static constant strings, such as string literals. If the string is not +immutable, the XOEF_RETAIN flag must not be used. + +The functions xo_retain_clear() and xo_retain_clear_all() release +internal information on either a single format string or all format +strings, respectively. Neither is required, but the library will +retain this information until it is cleared or the process exits:: + + const char *fmt = "{:name} {:count/%d}\n"; + for (i = 0; i < 1000; i++) { + xo_open_instance("item"); + xo_emit_f(XOEF_RETAIN, fmt, name[i], count[i]); + } + xo_retain_clear(fmt); + +The retained information is kept as thread-specific data. + +Example +~~~~~~~ + +In this example, the value for the number of items in stock is emitted:: + + xo_emit("{P: }{Lwc:In stock}{:in-stock/%u}\n", + instock); + +This call will generate the following output:: + + TEXT: + In stock: 144 + XML: + 144 + JSON: + "in-stock": 144, + HTML: +
+
+
In stock
+
:
+
+
144
+
+ +Clearly HTML wins the verbosity award, and this output does +not include XOF_XPATH or XOF_INFO data, which would expand the +penultimate line to:: + +
144
diff --git a/doc/field-modifiers.rst b/doc/field-modifiers.rst new file mode 100644 index 000000000000..9c8f2cdac89c --- /dev/null +++ b/doc/field-modifiers.rst @@ -0,0 +1,353 @@ + +.. index:: Field Modifiers +.. _field-modifiers: + +Field Modifiers +~~~~~~~~~~~~~~~ + +Field modifiers are flags which modify the way content emitted for +particular output styles: + +=== =============== =================================================== + M Name Description +=== =============== =================================================== + a argument The content appears as a 'const char \*' argument + c colon A colon (":") is appended after the label + d display Only emit field for display styles (text/HTML) + e encoding Only emit for encoding styles (XML/JSON) + g gettext Call gettext on field's render content + h humanize (hn) Format large numbers in human-readable style +\ hn-space Humanize: Place space between numeric and unit +\ hn-decimal Humanize: Add a decimal digit, if number < 10 +\ hn-1000 Humanize: Use 1000 as divisor instead of 1024 + k key Field is a key, suitable for XPath predicates + l leaf-list Field is a leaf-list + n no-quotes Do not quote the field when using JSON style + p plural Gettext: Use comma-separated plural form + q quotes Quote the field when using JSON style + t trim Trim leading and trailing whitespace + w white A blank (" ") is appended after the label +=== =============== =================================================== + +Roles and modifiers can also use more verbose names, when preceded by +a comma. For example, the modifier string "Lwc" (or "L,white,colon") +means the field has a label role (text that describes the next field) +and should be followed by a colon ('c') and a space ('w'). The +modifier string "Vkq" (or ":key,quote") means the field has a value +role (the default role), that it is a key for the current instance, +and that the value should be quoted when encoded for JSON. + +.. index:: Field Modifiers; Argument +.. _argument-modifier: + +The Argument Modifier ({a:}) +++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Argument + +The argument modifier indicates that the content of the field +descriptor will be placed as a UTF-8 string (const char \*) argument +within the xo_emit parameters:: + + EXAMPLE: + xo_emit("{La:} {a:}\n", "Label text", "label", "value"); + TEXT: + Label text value + JSON: + "label": "value" + XML: + + +The argument modifier allows field names for value fields to be passed +on the stack, avoiding the need to build a field descriptor using +snprintf. For many field roles, the argument modifier is not needed, +since those roles have specific mechanisms for arguments, such as +"{C:fg-%s}". + +.. index:: Field Modifiers; Colon +.. _colon-modifier: + +The Colon Modifier ({c:}) ++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Colon + +The colon modifier appends a single colon to the data value:: + + EXAMPLE: + xo_emit("{Lc:Name}{:name}\n", "phil"); + TEXT: + Name:phil + +The colon modifier is only used for the TEXT and HTML output +styles. It is commonly combined with the space modifier ('{w:}'). +It is purely a convenience feature. + +.. index:: Field Modifiers; Display +.. _display-modifier: + +The Display Modifier ({d:}) ++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Display + +The display modifier indicated the field should only be generated for +the display output styles, TEXT and HTML:: + + EXAMPLE: + xo_emit("{Lcw:Name}{d:name} {:id/%d}\n", "phil", 1); + TEXT: + Name: phil 1 + XML: + 1 + +The display modifier is the opposite of the encoding modifier, and +they are often used to give to distinct views of the underlying data. + +.. index:: Field Modifiers; Encoding +.. _encoding-modifier: + +The Encoding Modifier ({e:}) +++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Encoding + +The display modifier indicated the field should only be generated for +the display output styles, TEXT and HTML:: + + EXAMPLE: + xo_emit("{Lcw:Name}{:name} {e:id/%d}\n", "phil", 1); + TEXT: + Name: phil + XML: + phil1 + +The encoding modifier is the opposite of the display modifier, and +they are often used to give to distinct views of the underlying data. + +.. index:: Field Modifiers; Gettext +.. _gettext-modifier: + +The Gettext Modifier ({g:}) ++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Gettext +.. index:: gettext + +The gettext modifier is used to translate individual fields using the +gettext domain (typically set using the "`{G:}`" role) and current +language settings. Once libxo renders the field value, it is passed +to gettext(3), where it is used as a key to find the native language +translation. + +In the following example, the strings "State" and "full" are passed +to gettext() to find locale-based translated strings:: + + xo_emit("{Lgwc:State}{g:state}\n", "full"); + +See :ref:`gettext-role`, :ref:`plural-modifier`, and +:ref:`i18n` for additional details. + +.. index:: Field Modifiers; Humanize +.. _humanize-modifier: + +The Humanize Modifier ({h:}) +++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Humanize + +The humanize modifier is used to render large numbers as in a +human-readable format. While numbers like "44470272" are completely +readable to computers and savants, humans will generally find "44M" +more meaningful. + +"hn" can be used as an alias for "humanize". + +The humanize modifier only affects display styles (TEXT and HMTL). +The "`no-humanize`" option (See :ref:`options`) will block +the function of the humanize modifier. + +There are a number of modifiers that affect details of humanization. +These are only available in as full names, not single characters. The +"`hn-space`" modifier places a space between the number and any +multiplier symbol, such as "M" or "K" (ex: "44 K"). The +"`hn-decimal`" modifier will add a decimal point and a single tenths +digit when the number is less than 10 (ex: "4.4K"). The "`hn-1000`" +modifier will use 1000 as divisor instead of 1024, following the +JEDEC-standard instead of the more natural binary powers-of-two +tradition:: + + EXAMPLE: + xo_emit("{h:input/%u}, {h,hn-space:output/%u}, " + "{h,hn-decimal:errors/%u}, {h,hn-1000:capacity/%u}, " + "{h,hn-decimal:remaining/%u}\n", + input, output, errors, capacity, remaining); + TEXT: + 21, 57 K, 96M, 44M, 1.2G + +In the HTML style, the original numeric value is rendered in the +"data-number" attribute on the
element:: + +
96M
+ +.. index:: Field Modifiers; Key +.. _key-modifier: + +The Key Modifier ({k:}) ++++++++++++++++++++++++ + +.. index:: Field Modifiers; Key + +The key modifier is used to indicate that a particular field helps +uniquely identify an instance of list data:: + + EXAMPLE: + xo_open_list("user"); + for (i = 0; i < num_users; i++) { + xo_open_instance("user"); + xo_emit("User {k:name} has {:count} tickets\n", + user[i].u_name, user[i].u_tickets); + xo_close_instance("user"); + } + xo_close_list("user"); + +.. index:: XOF_XPATH + +Currently the key modifier is only used when generating XPath value +for the HTML output style when XOF_XPATH is set, but other uses are +likely in the near future. + +.. index:: Field Modifiers; Leaf-List +.. _leaf-list: + +The Leaf-List Modifier ({l:}) ++++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Leaf-List + +The leaf-list modifier is used to distinguish lists where each +instance consists of only a single value. In XML, these are +rendered as single elements, where JSON renders them as arrays:: + + EXAMPLE: + for (i = 0; i < num_users; i++) { + xo_emit("Member {l:user}\n", user[i].u_name); + } + XML: + phil + pallavi + JSON: + "user": [ "phil", "pallavi" ] + +The name of the field must match the name of the leaf list. + +.. index:: Field Modifiers; No-Quotes +.. _no-quotes-modifier: + +The No-Quotes Modifier ({n:}) ++++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; No-Quotes + +The no-quotes modifier (and its twin, the 'quotes' modifier) affect +the quoting of values in the JSON output style. JSON uses quotes for +string value, but no quotes for numeric, boolean, and null data. +xo_emit applies a simple heuristic to determine whether quotes are +needed, but often this needs to be controlled by the caller:: + + EXAMPLE: + const char *bool = is_true ? "true" : "false"; + xo_emit("{n:fancy/%s}", bool); + JSON: + "fancy": true + +.. index:: Field Modifiers; Plural +.. _plural-modifier: + +The Plural Modifier ({p:}) +++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Plural +.. index:: gettext + +The plural modifier selects the appropriate plural form of an +expression based on the most recent number emitted and the current +language settings. The contents of the field should be the singular +and plural English values, separated by a comma:: + + xo_emit("{:bytes} {Ngp:byte,bytes}\n", bytes); + +The plural modifier is meant to work with the gettext modifier ({g:}) +but can work independently. See :ref:`gettext-modifier`. + +When used without the gettext modifier or when the message does not +appear in the message catalog, the first token is chosen when the last +numeric value is equal to 1; otherwise the second value is used, +mimicking the simple pluralization rules of English. + +When used with the gettext modifier, the ngettext(3) function is +called to handle the heavy lifting, using the message catalog to +convert the singular and plural forms into the native language. + +.. index:: Field Modifiers; Quotes +.. _quotes-modifier: + +The Quotes Modifier ({q:}) +++++++++++++++++++++++++++ + +.. index:: Field Modifiers; Quotes + +The quotes modifier (and its twin, the 'no-quotes' modifier) affect +the quoting of values in the JSON output style. JSON uses quotes for +string value, but no quotes for numeric, boolean, and null data. +xo_emit applies a simple heuristic to determine whether quotes are +needed, but often this needs to be controlled by the caller:: + + EXAMPLE: + xo_emit("{q:time/%d}", 2014); + JSON: + "year": "2014" + +The heuristic is based on the format; if the format uses any of the +following conversion specifiers, then no quotes are used:: + + d i o u x X D O U e E f F g G a A c C p + +.. index:: Field Modifiers; Trim +.. _trim-modifier: + +The Trim Modifier ({t:}) +++++++++++++++++++++++++ + +.. index:: Field Modifiers; Trim + +The trim modifier removes any leading or trailing whitespace from +the value:: + + EXAMPLE: + xo_emit("{t:description}", " some input "); + JSON: + "description": "some input" + +.. index:: Field Modifiers; White Space +.. _white-space-modifier: + +The White Space Modifier ({w:}) ++++++++++++++++++++++++++++++++ + +.. index:: Field Modifiers; White Space + +The white space modifier appends a single space to the data value:: + + EXAMPLE: + xo_emit("{Lw:Name}{:name}\n", "phil"); + TEXT: + Name phil + +The white space modifier is only used for the TEXT and HTML output +styles. It is commonly combined with the colon modifier ('{c:}'). +It is purely a convenience feature. + +Note that the sense of the 'w' modifier is reversed for the units role +({Uw:}); a blank is added before the contents, rather than after it. diff --git a/doc/field-roles.rst b/doc/field-roles.rst new file mode 100644 index 000000000000..81f890b493b3 --- /dev/null +++ b/doc/field-roles.rst @@ -0,0 +1,310 @@ + +.. index:: Field Roles +.. _field-roles: + +Field Roles +~~~~~~~~~~~ + +Field roles are optional, and indicate the role and formatting of the +content. The roles are listed below; only one role is permitted: + +=== ============== ================================================= +R Name Description +=== ============== ================================================= +C color Field has color and effect controls +D decoration Field is non-text (e.g., colon, comma) +E error Field is an error message +G gettext Call gettext(3) on the format string +L label Field is text that prefixes a value +N note Field is text that follows a value +P padding Field is spaces needed for vertical alignment +T title Field is a title value for headings +U units Field is the units for the previous value field +V value Field is the name of field (the default) +W warning Field is a warning message +[ start-anchor Begin a section of anchored variable-width text +] stop-anchor End a section of anchored variable-width text +=== ============== ================================================= + + EXAMPLE: + xo_emit("{L:Free}{D::}{P: }{:free/%u} {U:Blocks}\n", + free_blocks); + +When a role is not provided, the "*value*" role is used as the default. + +Roles and modifiers can also use more verbose names, when preceded by +a comma:: + + EXAMPLE: + xo_emit("{,label:Free}{,decoration::}{,padding: }" + "{,value:free/%u} {,units:Blocks}\n", + free_blocks); + +.. index:: Field Roles; Color +.. _color-role: + +The Color Role ({C:}) ++++++++++++++++++++++ + +Colors and effects control how text values are displayed; they are +used for display styles (TEXT and HTML):: + + xo_emit("{C:bold}{:value}{C:no-bold}\n", value); + +Colors and effects remain in effect until modified by other "C"-role +fields:: + + xo_emit("{C:bold}{C:inverse}both{C:no-bold}only inverse\n"); + +If the content is empty, the "*reset*" action is performed:: + + xo_emit("{C:both,underline}{:value}{C:}\n", value); + +The content should be a comma-separated list of zero or more colors or +display effects:: + + xo_emit("{C:bold,inverse}Ugly{C:no-bold,no-inverse}\n"); + +The color content can be either static, when placed directly within +the field descriptor, or a printf-style format descriptor can be used, +if preceded by a slash ("/"): + + xo_emit("{C:/%s%s}{:value}{C:}", need_bold ? "bold" : "", + need_underline ? "underline" : "", value); + +Color names are prefixed with either "fg-" or "bg-" to change the +foreground and background colors, respectively:: + + xo_emit("{C:/fg-%s,bg-%s}{Lwc:Cost}{:cost/%u}{C:reset}\n", + fg_color, bg_color, cost); + +The following table lists the supported effects: + +=============== ================================================= + Name Description +=============== ================================================= + bg-XXXXX Change background color + bold Start bold text effect + fg-XXXXX Change foreground color + inverse Start inverse (aka reverse) text effect + no-bold Stop bold text effect + no-inverse Stop inverse (aka reverse) text effect + no-underline Stop underline text effect + normal Reset effects (only) + reset Reset colors and effects (restore defaults) + underline Start underline text effect +=============== ================================================= + +The following color names are supported: + +========= ============================================ + Name Description +========= ============================================ + black + blue + cyan + default Default color for foreground or background + green + magenta + red + white + yellow +========= ============================================ + +When using colors, the developer should remember that users will +change the foreground and background colors of terminal session +according to their own tastes, so assuming that "blue" looks nice is +never safe, and is a constant annoyance to your dear author. In +addition, a significant percentage of users (1 in 12) will be color +blind. Depending on color to convey critical information is not a +good idea. Color should enhance output, but should not be used as the +sole means of encoding information. + +.. index:: Field Roles; Decoration +.. _decoration-role: + +The Decoration Role ({D:}) +++++++++++++++++++++++++++ + +Decorations are typically punctuation marks such as colons, +semi-colons, and commas used to decorate the text and make it simpler +for human readers. By marking these distinctly, HTML usage scenarios +can use CSS to direct their display parameters:: + + xo_emit("{D:((}{:name}{D:))}\n", name); + +.. index:: Field Roles; Gettext +.. _gettext-role: + +The Gettext Role ({G:}) ++++++++++++++++++++++++ + +libxo supports internationalization (i18n) through its use of +gettext(3). Use the "{G:}" role to request that the remaining part of +the format string, following the "{G:}" field, be handled using +gettext(). + +Since gettext() uses the string as the key into the message catalog, +libxo uses a simplified version of the format string that removes +unimportant field formatting and modifiers, stopping minor formatting +changes from impacting the expensive translation process. A developer +change such as changing "/%06d" to "/%08d" should not force hand +inspection of all .po files. + +The simplified version can be generated for a single message using the +"`xopo -s $text`" command, or an entire .pot can be translated using +the "`xopo -f $input -o $output`" command. + + xo_emit("{G:}Invalid token\n"); + +The {G:} role allows a domain name to be set. gettext calls will +continue to use that domain name until the current format string +processing is complete, enabling a library function to emit strings +using it's own catalog. The domain name can be either static as the +content of the field, or a format can be used to get the domain name +from the arguments. + + xo_emit("{G:libc}Service unavailable in restricted mode\n"); + +See :ref:`i18n` for additional details. + +.. index:: Field Roles; Label +.. _label-role: + +The Label Role ({L:}) ++++++++++++++++++++++ + +Labels are text that appears before a value:: + + xo_emit("{Lwc:Cost}{:cost/%u}\n", cost); + +.. index:: Field Roles; Note +.. _note-role: + +The Note Role ({N:}) +++++++++++++++++++++ + +Notes are text that appears after a value:: + + xo_emit("{:cost/%u} {N:per year}\n", cost); + +.. index:: Field Roles; Padding +.. _padding-role: + +The Padding Role ({P:}) ++++++++++++++++++++++++ + +Padding represents whitespace used before and between fields. + +The padding content can be either static, when placed directly within +the field descriptor, or a printf-style format descriptor can be used, +if preceded by a slash ("/"):: + + xo_emit("{P: }{Lwc:Cost}{:cost/%u}\n", cost); + xo_emit("{P:/%30s}{Lwc:Cost}{:cost/%u}\n", "", cost); + +.. index:: Field Roles; Title +.. _title-role: + +The Title Role ({T:}) ++++++++++++++++++++++ + +Title are heading or column headers that are meant to be displayed to +the user. The title can be either static, when placed directly within +the field descriptor, or a printf-style format descriptor can be used, +if preceded by a slash ("/"):: + + xo_emit("{T:Interface Statistics}\n"); + xo_emit("{T:/%20.20s}{T:/%6.6s}\n", "Item Name", "Cost"); + +Title fields have an extra convenience feature; if both content and +format are specified, instead of looking to the argument list for a +value, the content is used, allowing a mixture of format and content +within the field descriptor:: + + xo_emit("{T:Name/%20s}{T:Count/%6s}\n"); + +Since the incoming argument is a string, the format must be "%s" or +something suitable. + +.. index:: Field Roles; Units +.. index:: XOF_UNITS +.. _units-role: + +The Units Role ({U:}) ++++++++++++++++++++++ + +Units are the dimension by which values are measured, such as degrees, +miles, bytes, and decibels. The units field carries this information +for the previous value field:: + + xo_emit("{Lwc:Distance}{:distance/%u}{Uw:miles}\n", miles); + +Note that the sense of the 'w' modifier is reversed for units; +a blank is added before the contents, rather than after it. + +When the XOF_UNITS flag is set, units are rendered in XML as the +"units" attribute:: + + 50 + +Units can also be rendered in HTML as the "data-units" attribute:: + +
50
+ +.. index:: Field Roles; Value +.. _value-role: + +The Value Role ({V:} and {:}) ++++++++++++++++++++++++++++++ + +The value role is used to represent the a data value that is +interesting for the non-display output styles (XML and JSON). Value +is the default role; if no other role designation is given, the field +is a value. The field name must appear within the field descriptor, +followed by one or two format descriptors. The first format +descriptor is used for display styles (TEXT and HTML), while the +second one is used for encoding styles (XML and JSON). If no second +format is given, the encoding format defaults to the first format, +with any minimum width removed. If no first format is given, both +format descriptors default to "%s":: + + xo_emit("{:length/%02u}x{:width/%02u}x{:height/%02u}\n", + length, width, height); + xo_emit("{:author} wrote \"{:poem}\" in {:year/%4d}\n, + author, poem, year); + +.. index:: Field Roles; Anchor +.. _anchor-role: + +The Anchor Roles ({[:} and {]:}) +++++++++++++++++++++++++++++++++ + +The anchor roles allow a set of strings by be padded as a group, +but still be visible to xo_emit as distinct fields. Either the start +or stop anchor can give a field width and it can be either directly in +the descriptor or passed as an argument. Any fields between the start +and stop anchor are padded to meet the minimum width given. + +To give a width directly, encode it as the content of the anchor tag:: + + xo_emit("({[:10}{:min/%d}/{:max/%d}{]:})\n", min, max); + +To pass a width as an argument, use "%d" as the format, which must +appear after the "/". Note that only "%d" is supported for widths. +Using any other value could ruin your day:: + + xo_emit("({[:/%d}{:min/%d}/{:max/%d}{]:})\n", width, min, max); + +If the width is negative, padding will be added on the right, suitable +for left justification. Otherwise the padding will be added to the +left of the fields between the start and stop anchors, suitable for +right justification. If the width is zero, nothing happens. If the +number of columns of output between the start and stop anchors is less +than the absolute value of the given width, nothing happens. + +.. index:: XOF_WARN + +Widths over 8k are considered probable errors and not supported. If +XOF_WARN is set, a warning will be generated. diff --git a/doc/format-strings.rst b/doc/format-strings.rst new file mode 100644 index 000000000000..44e02abd41e7 --- /dev/null +++ b/doc/format-strings.rst @@ -0,0 +1,47 @@ + +.. index:: Format Strings +.. _format-strings: + +Format Strings +-------------- + +libxo uses format strings to control the rendering of data into the +various output styles. Each format string contains a set of zero or +more field descriptions, which describe independent data fields. Each +field description contains a set of modifiers, a content string, and +zero, one, or two format descriptors. The modifiers tell libxo what +the field is and how to treat it, while the format descriptors are +formatting instructions using printf-style format strings, telling +libxo how to format the field. The field description is placed inside +a set of braces, with a colon (":") after the modifiers and a slash +("/") before each format descriptors. Text may be intermixed with +field descriptions within the format string. + +The field description is given as follows:: + + '{' [ role | modifier ]* [',' long-names ]* ':' [ content ] + [ '/' field-format [ '/' encoding-format ]] '}' + +The role describes the function of the field, while the modifiers +enable optional behaviors. The contents, field-format, and +encoding-format are used in varying ways, based on the role. These +are described in the following sections. + +In the following example, three field descriptors appear. The first +is a padding field containing three spaces of padding, the second is a +label ("In stock"), and the third is a value field ("in-stock"). The +in-stock field has a "%u" format that will parse the next argument +passed to the xo_emit function as an unsigned integer:: + + xo_emit("{P: }{Lwc:In stock}{:in-stock/%u}\n", 65); + +This single line of code can generate text (" In stock: 65\n"), XML +("65"), JSON ('"in-stock": 6'), or HTML (too +lengthy to be listed here). + +While roles and modifiers typically use single character for brevity, +there are alternative names for each which allow more verbose +formatting strings. These names must be preceded by a comma, and may +follow any single-character values:: + + xo_emit("{L,white,colon:In stock}{,key:in-stock/%u}\n", 65); diff --git a/doc/formatting.rst b/doc/formatting.rst new file mode 100644 index 000000000000..dbbdd24dfcc8 --- /dev/null +++ b/doc/formatting.rst @@ -0,0 +1,165 @@ + +Formatting with libxo +===================== + +Most unix commands emit text output aimed at humans. It is designed +to be parsed and understood by a user. Humans are gifted at +extracting details and pattern matching in such output. Often +programmers need to extract information from this human-oriented +output. Programmers use tools like grep, awk, and regular expressions +to ferret out the pieces of information they need. Such solutions are +fragile and require maintenance when output contents change or evolve, +along with testing and validation. + +Modern tool developers favor encoding schemes like XML and JSON, +which allow trivial parsing and extraction of data. Such formats are +simple, well understood, hierarchical, easily parsed, and often +integrate easier with common tools and environments. Changes to +content can be done in ways that do not break existing users of the +data, which can reduce maintenance costs and increase feature velocity. + +In addition, modern reality means that more output ends up in web +browsers than in terminals, making HTML output valuable. + +libxo allows a single set of function calls in source code to generate +traditional text output, as well as XML and JSON formatted data. HTML +can also be generated; "
" elements surround the traditional text +output, with attributes that detail how to render the data. + +A single libxo function call in source code is all that's required:: + + xo_emit("Connecting to {:host}.{:domain}...\n", host, domain); + + TEXT: + Connecting to my-box.example.com... + XML: + my-box + example.com + JSON: + "host": "my-box", + "domain": "example.com" + HTML: +
+
Connecting to
+
my-box
+
.
+
example.com
+
...
+
+ +Encoding Styles +--------------- + +There are four encoding styles supported by libxo: + +- TEXT output can be display on a terminal session, allowing + compatibility with traditional command line usage. +- XML output is suitable for tools like XPath and protocols like + NETCONF. +- JSON output can be used for RESTful APIs and integration with + languages like Javascript and Python. +- HTML can be matched with a small CSS file to permit rendering in any + HTML5 browser. + +In general, XML and JSON are suitable for encoding data, while TEXT is +suited for terminal output and HTML is suited for display in a web +browser (see :ref:`xohtml`). + +Text Output +~~~~~~~~~~~ + +Most traditional programs generate text output on standard output, +with contents like:: + + 36 ./src + 40 ./bin + 90 . + +In this example (taken from *du* source code), the code to generate this +data might look like:: + + printf("%d\t%s\n", num_blocks, path); + +Simple, direct, obvious. But it's only making text output. Imagine +using a single code path to make TEXT, XML, JSON or HTML, deciding at +run time which to generate. + +libxo expands on the idea of printf format strings to make a single +format containing instructions for creating multiple output styles:: + + xo_emit("{:blocks/%d}\t{:path/%s}\n", num_blocks, path); + +This line will generate the same text output as the earlier printf +call, but also has enough information to generate XML, JSON, and HTML. + +The following sections introduce the other formats. + +XML Output +~~~~~~~~~~ + +XML output consists of a hierarchical set of elements, each encoded +with a start tag and an end tag. The element should be named for data +value that it is encoding:: + + + 36 + ./src + + + 40 + ./bin + + + 90 + . + + +`XML`_ is the W3C standard for encoding data. + +.. _XML: https://w3c.org/TR/xml + +JSON Output +~~~~~~~~~~~ + +JSON output consists of a hierarchical set of objects and lists, each +encoded with a quoted name, a colon, and a value. If the value is a +string, it must be quoted, but numbers are not quoted. Objects are +encoded using braces; lists are encoded using square brackets. +Data inside objects and lists is separated using commas:: + + items: [ + { "blocks": 36, "path" : "./src" }, + { "blocks": 40, "path" : "./bin" }, + { "blocks": 90, "path" : "./" } + ] + +HTML Output +~~~~~~~~~~~ + +HTML output is designed to allow the output to be rendered in a web +browser with minimal effort. Each piece of output data is rendered +inside a
element, with a class name related to the role of the +data. By using a small set of class attribute values, a CSS +stylesheet can render the HTML into rich text that mirrors the +traditional text content. + +Additional attributes can be enabled to provide more details about the +data, including data type, description, and an XPath location:: + +
+
36
+
+
./src
+
+
+
40
+
+
./bin
+
+
+
90
+
+
./
+
diff --git a/doc/getting.rst b/doc/getting.rst new file mode 100644 index 000000000000..1511aada5a1e --- /dev/null +++ b/doc/getting.rst @@ -0,0 +1,185 @@ + +.. index:: Getting libxo + +Getting libxo +============= + +libxo now ships as part of the FreeBSD Operating System (as of Release +11). + +libxo source code lives on github: + + https://github.com/Juniper/libxo + +The latest release of libxo is available at: + + https://github.com/Juniper/libxo/releases + +We're using `Semantic Versioning`_ to number our releases. libxo is +open source, distributed under the BSD license. We follow the +branching scheme from `A Successful Git Branching Model`_: +we do development under the "*develop*" branch, and release from +the "*master*" branch. To clone a developer tree, run the following +command:: + + git clone https://github.com/Juniper/libxo.git -b develop + +.. _Semantic Versioning: http://semver.org/spec/v2.0.0.html +.. _A Successful Git Branching Model: + http://nvie.com/posts/a-successful-git-branching-model + +Issues, problems, and bugs should be directly to the issues page on +our github site. + +Downloading libxo Source Code +----------------------------- + +You can retrieve the source for libxo in two ways: + +A. Use a "distfile" for a specific release. We use github to maintain + our releases. Visit the `release page`_ to see the list of + releases. To download the latest, look for the release witeh the + green "Latest release" button and the green "libxo-RELEASE.tar.gz" + button under that section. + +.. _release page: https://github.com/Juniper/libxo/releases + + After downloading that release's distfile, untar it as follows:: + + tar -zxf libxo-RELEASE.tar.gz + cd libxo-RELEASE + + .. admonition:: Solaris Users + + Note: for Solaris users, your "`tar`" command lacks the "-z" flag, + so you'll need to substitute "`gzip -dc $file | tar xf -`" instead + of "`tar -zxf $file`". + +B. Use the current build from github. This gives you the most recent + source code, which might be less stable than a specific release. To + build libxo from the git repo:: + + git clone https://github.com/Juniper/libxo.git + cd libxo + + .. admonition:: Be Aware + + The github repository does **not** contain the files generated by + "*autoreconf*", with the notable exception of the "*m4*" directory. + Since these files (depcomp, configure, missing, install-sh, etc) are + generated files, we keep them out of the source code repository. + + This means that if you download the a release distfile, these files + will be ready and you'll just need to run "configure", but if you + download the source code from svn, then you'll need to run + "*autoreconf*" by hand. This step is done for you by the "*setup.sh*" + script, described in the next section. + +.. _building: + +Building libxo +-------------- + +To build libxo, you'll need to set up the build, run the "*configure*" +script, run the "*make*" command, and run the regression tests. + +The following is a summary of the commands needed. These commands are +explained in detail in the rest of this section:: + + sh bin/setup.sh + cd build + ../configure + make + make test + sudo make install + +The following sections will walk through each of these steps with +additional details and options, but the above directions should be all +that's needed. + +Setting up the build +~~~~~~~~~~~~~~~~~~~~ + +.. admonition: Note + + If you downloaded a distfile, you can skip this step. + +Run the "*setup.sh*" script to set up the build. This script runs the +"*autoreconf*" command to generate the "*configure*" script and other +generated files:: + + sh bin/setup.sh + +Note: We're are currently using autoreconf version 2.69. + +Running the "configure" Script +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Configure (and autoconf in general) provides a means of building +software in diverse environments. Our configure script supports +a set of options that can be used to adjust to your operating +environment. Use "`configure --help`" to view these options. + +We use the "*build*" directory to keep object files and generated files +away from the source tree. + +To run the configure script, change into the "*build*" directory, and +run the "*configure*" script. Add any required options to the +"`../configure`" command line:: + + cd build + ../configure + +Expect to see the "*configure*" script generate the following error:: + + /usr/bin/rm: cannot remove `libtoolT': No such file or directory + +This error is harmless and can be safely ignored. + +By default, libxo installs architecture-independent files, including +extension library files, in the /usr/local directories. To specify an +installation prefix other than /usr/local for all installation files, +include the --prefix=prefix option and specify an alternate +location. To install just the extension library files in a different, +user-defined location, include the "*--with-extensions-dir=dir*" option +and specify the location where the extension libraries will live:: + + cd build + ../configure [OPTION]... [VAR=VALUE]... + +Running the "make" Command +++++++++++++++++++++++++++ + +Once the "*configure*" script is run, build the images using the +"`make`" command:: + + make + +Running the Regression Tests +++++++++++++++++++++++++++++ + +libxo includes a set of regression tests that can be run to ensure +the software is working properly. These test are optional, but will +help determine if there are any issues running libxo on your +machine. To run the regression tests:: + + make test + +Installing libxo +~~~~~~~~~~~~~~~~ + +Once the software is built, you'll need to install libxo using the +"`make install`" command. If you are the root user, or the owner of +the installation directory, simply issue the command:: + + make install + +If you are not the "*root*" user and are using the "*sudo*" package, use:: + + sudo make install + +Verify the installation by viewing the output of "`xo --version`":: + + % xo --version + libxo version 0.3.5-git-develop + xo version 0.3.5-git-develop diff --git a/doc/howto.rst b/doc/howto.rst new file mode 100644 index 000000000000..513572355bbc --- /dev/null +++ b/doc/howto.rst @@ -0,0 +1,394 @@ + +Howtos: Focused Directions +========================== + +This section provides task-oriented instructions for selected tasks. +If you have a task that needs instructions, please open a request as +an enhancement issue on github. + +Howto: Report bugs +------------------ + +libxo uses github to track bugs or request enhancements. Please use +the following URL: + + https://github.com/Juniper/libxo/issues + +Howto: Install libxo +-------------------- + +libxo is open source, under a new BSD license. Source code is +available on github, as are recent releases. To get the most +current release, please visit: + + https://github.com/Juniper/libxo/releases + +After downloading and untarring the source code, building involves the +following steps:: + + sh bin/setup.sh + cd build + ../configure + make + make test + sudo make install + +libxo uses a distinct "*build*" directory to keep generated files +separated from source files. + +.. index:: configure + +Use "`../configure --help`" to display available configuration +options, which include the following:: + + --enable-warnings Turn on compiler warnings + --enable-debug Turn on debugging + --enable-text-only Turn on text-only rendering + --enable-printflike Enable use of GCC __printflike attribute + --disable-libxo-options Turn off support for LIBXO_OPTIONS + --with-gettext=PFX Specify location of gettext installation + --with-libslax-prefix=PFX Specify location of libslax config + +Compiler warnings are a very good thing, but recent compiler version +have added some very pedantic checks. While every attempt is made to +keep libxo code warning-free, warnings are now optional. If you are +doing development work on libxo, it is required that you +use --enable-warnings to keep the code warning free, but most users +need not use this option. + +.. index:: --enable-text-only + +libxo provides the `--enable-text-only` option to reduce the +footprint of the library for smaller installations. XML, JSON, and +HTML rendering logic is removed. + +.. index:: --with-gettext + +The gettext library does not provide a simple means of learning its +location, but libxo will look for it in /usr and /opt/local. If +installed elsewhere, the installer will need to provide this +information using the "`--with-gettext=/dir/path`" option. + +.. index:: libslax + +libslax is not required by libxo; it contains the "oxtradoc" program +used to format documentation. + +For additional information, see :ref:`building`. + +Howto: Convert command line applications +---------------------------------------- + +Common question: How do I convert an existing command line application? + +There are four basic steps for converting command line application to +use libxo:: + +- Setting up the context +- Converting printf calls +- Creating hierarchy +- Converting error functions + +Setting up the context +~~~~~~~~~~~~~~~~~~~~~~ + +To use libxo, you'll need to include the "xo.h" header file in your +source code files:: + + #include + +In your main() function, you'll need to call xo_parse_args to handling +argument parsing (:ref:`xo_parse_args`). This function removes +libxo-specific arguments the program's argv and returns either the +number of remaining arguments or -1 to indicate an error:: + + int + main (int argc, char **argv) + { + argc = xo_parse_args(argc, argv); + if (argc < 0) + return argc; + .... + } + +.. index:: atexit +.. index:: xo_finish_atexit + +At the bottom of your main(), you'll need to call xo_finish() to +complete output processing for the default handle (:ref:`handles`). This +is required to flush internal information buffers. libxo provides the +xo_finish_atexit function that is suitable for use with the +:manpage:`atexit(3)` function:: + + atexit(xo_finish_atexit); + +Converting printf Calls +~~~~~~~~~~~~~~~~~~~~~~~ + +The second task is inspecting code for :manpage:`printf(3)` calls and +replacing them with xo_emit() calls. The format strings are similar +in task, but libxo format strings wrap output fields in braces. The +following two calls produce identical text output:: + + OLD:: + printf("There are %d %s events\n", count, etype); + + NEW:: + xo_emit("There are {:count/%d} {:event} events\n", count, etype); + +"count" and "event" are used as names for JSON and XML output. The +"count" field uses the format "%d" and "event" uses the default "%s" +format. Both are "value" roles, which is the default role. + +Since text outside of output fields is passed verbatim, other roles +are less important, but their proper use can help make output more +useful. The "note" and "label" roles allow HTML output to recognize +the relationship between text and the associated values, allowing +appropriate "hover" and "onclick" behavior. Using the "units" role +allows the presentation layer to perform conversions when needed. The +"warning" and "error" roles allows use of color and font to draw +attention to warnings. The "padding" role makes the use of vital +whitespace more clear (:ref:`padding-role`). + +The "*title*" role indicates the headings of table and sections. This +allows HTML output to use CSS to make this relationship more obvious:: + + OLD:: + printf("Statistics:\n"); + + NEW:: + xo_emit("{T:Statistics}:\n"); + +The "*color*" roles controls foreground and background colors, as well +as effects like bold and underline (see :ref:`color-role`):: + + NEW:: + xo_emit("{C:bold}required{C:}\n"); + +Finally, the start- and stop-anchor roles allow justification and +padding over multiple fields (see :ref:`anchor-role`):: + + OLD:: + snprintf(buf, sizeof(buf), "(%u/%u/%u)", min, ave, max); + printf("%30s", buf); + + NEW:: + xo_emit("{[:30}({:minimum/%u}/{:average/%u}/{:maximum/%u}{]:}", + min, ave, max); + +Creating Hierarchy +~~~~~~~~~~~~~~~~~~ + +Text output doesn't have any sort of hierarchy, but XML and JSON +require this. Typically applications use indentation to represent +these relationship:: + + OLD:: + printf("table %d\n", tnum); + for (i = 0; i < tmax; i++) { + printf(" %s %d\n", table[i].name, table[i].size); + } + + NEW:: + xo_emit("{T:/table %d}\n", tnum); + xo_open_list("table"); + for (i = 0; i < tmax; i++) { + xo_open_instance("table"); + xo_emit("{P: }{k:name} {:size/%d}\n", + table[i].name, table[i].size); + xo_close_instance("table"); + } + xo_close_list("table"); + +The open and close list functions are used before and after the list, +and the open and close instance functions are used before and after +each instance with in the list. + +Typically these developer looks for a "for" loop as an indication of +where to put these calls. + +In addition, the open and close container functions allow for +organization levels of hierarchy:: + + OLD:: + printf("Paging information:\n"); + printf(" Free: %lu\n", free); + printf(" Active: %lu\n", active); + printf(" Inactive: %lu\n", inactive); + + NEW:: + xo_open_container("paging-information"); + xo_emit("{P: }{L:Free: }{:free/%lu}\n", free); + xo_emit("{P: }{L:Active: }{:active/%lu}\n", active); + xo_emit("{P: }{L:Inactive: }{:inactive/%lu}\n", inactive); + xo_close_container("paging-information"); + +Converting Error Functions +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +libxo provides variants of the standard error and warning functions, +:manpage:`err(3)` and :manpage:`warn(3)`. There are two variants, one +for putting the errors on standard error, and the other writes the +errors and warnings to the handle using the appropriate encoding +style:: + + OLD:: + err(1, "cannot open output file: %s", file); + + NEW:: + xo_err(1, "cannot open output file: %s", file); + xo_emit_err(1, "cannot open output file: {:filename}", file); + +.. index:: xo_finish + +Call xo_finish +~~~~~~~~~~~~~~ + +One important item: call `xo_finish` at the end of your program so +ensure that all buffered data is written out. You can call it +explicitly call it, or use :manpage:`atexit(3)` to have +`xo_finish_atexit` called implicitly on exit:: + + OLD:: + exit(0); + + NEW:: + xo_finish(); + exit(0); + +Howto: Use "xo" in Shell Scripts +-------------------------------- + +.. admonition:: Needed + + Documentation is needed for this area. + +.. index:: Internationalization (i18n) +.. index:: gettext +.. index:: xopo + +.. _i18n: + +Howto: Internationalization (i18n) +----------------------------------------------- + + How do I use libxo to support internationalization? + +libxo allows format and field strings to be used a keys into message +catalogs to enable translation into a user's native language by +invoking the standard :manpage:`gettext(3)` functions. + +gettext setup is a bit complicated: text strings are extracted from +source files into "*portable object template*" (.pot) files using the +`xgettext` command. For each language, this template file is used as +the source for a message catalog in the "*portable object*" (.po) +format, which are translated by hand and compiled into "*machine +object*" (.mo) files using the `msgfmt` command. The .mo files are +then typically installed in the /usr/share/locale or +/opt/local/share/locale directories. At run time, the user's language +settings are used to select a .mo file which is searched for matching +messages. Text strings in the source code are used as keys to look up +the native language strings in the .mo file. + +Since the xo_emit format string is used as the key into the message +catalog, libxo removes unimportant field formatting and modifiers from +the format string before use so that minor formatting changes will not +impact the expensive translation process. We don't want a developer +change such as changing "/%06d" to "/%08d" to force hand inspection of +all .po files. The simplified version can be generated for a single +message using the `xopo -s $text` command, or an entire .pot can be +translated using the `xopo -f $input -o $output` command:: + + EXAMPLE: + % xopo -s "There are {:count/%u} {:event/%.6s} events\n" + There are {:count} {:event} events\n + + Recommended workflow: + # Extract text messages + xgettext --default-domain=foo --no-wrap \ + --add-comments --keyword=xo_emit --keyword=xo_emit_h \ + --keyword=xo_emit_warn -C -E -n --foreign-user \ + -o foo.pot.raw foo.c + + # Simplify format strings for libxo + xopo -f foo.pot.raw -o foo.pot + + # For a new language, just copy the file + cp foo.pot po/LC/my_lang/foo.po + + # For an existing language: + msgmerge --no-wrap po/LC/my_lang/foo.po \ + foo.pot -o po/LC/my_lang/foo.po.new + + # Now the hard part: translate foo.po using tools + # like poedit or emacs' po-mode + + # Compile the finished file; Use of msgfmt's "-v" option is + # strongly encouraged, so that "fuzzy" entries are reported. + msgfmt -v -o po/my_lang/LC_MESSAGES/foo.mo po/my_lang/foo.po + + # Install the .mo file + sudo cp po/my_lang/LC_MESSAGES/foo.mo \ + /opt/local/share/locale/my_lang/LC_MESSAGE/ + +Once these steps are complete, you can use the `gettext` command to +test the message catalog:: + + gettext -d foo -e "some text" + +i18n and xo_emit +~~~~~~~~~~~~~~~~ + +There are three features used in libxo used to support i18n: + +- The "{G:}" role looks for a translation of the format string. +- The "{g:}" modifier looks for a translation of the field. +- The "{p:}" modifier looks for a pluralized version of the field. + +Together these three flags allows a single function call to give +native language support, as well as libxo's normal XML, JSON, and HTML +support:: + + printf(gettext("Received %zu %s from {g:server} server\n"), + counter, ngettext("byte", "bytes", counter), + gettext("web")); + + xo_emit("{G:}Received {:received/%zu} {Ngp:byte,bytes} " + "from {g:server} server\n", counter, "web"); + +libxo will see the "{G:}" role and will first simplify the format +string, removing field formats and modifiers:: + + "Received {:received} {N:byte,bytes} from {:server} server\n" + +libxo calls :manpage:`gettext(3)` with that string to get a localized +version. If your language were *Pig Latin*, the result might look +like:: + + "Eceivedray {:received} {N:byte,bytes} omfray " + "{:server} erversay\n" + +Note the field names do not change and they should not be translated. +The contents of the note ("byte,bytes") should also not be translated, +since the "g" modifier will need the untranslated value as the key for +the message catalog. + +The field "{g:server}" requests the rendered value of the field be +translated using :manpage:`gettext(3)`. In this example, "web" would +be used. + +The field "{Ngp:byte,bytes}" shows an example of plural form using the +"{p:}" modifier with the "{g:}" modifier. The base singular and plural +forms appear inside the field, separated by a comma. At run time, +libxo uses the previous field's numeric value to decide which form to +use by calling :manpage:`ngettext(3)`. + +If a domain name is needed, it can be supplied as the content of the +{G:} role. Domain names remain in use throughout the format string +until cleared with another domain name:: + + printf(dgettext("dns", "Host %s not found: %d(%s)\n"), + name, errno, dgettext("strerror", strerror(errno))); + + xo_emit("{G:dns}Host {:hostname} not found: " + "%d({G:strerror}{g:%m})\n", name, errno); diff --git a/doc/index.rst b/doc/index.rst new file mode 100644 index 000000000000..2c889ceaa496 --- /dev/null +++ b/doc/index.rst @@ -0,0 +1,53 @@ +.. # + # Copyright (c) 2014, Juniper Networks, Inc. + # All rights reserved. + # This SOFTWARE is licensed under the LICENSE provided in the + # ../Copyright file. By downloading, installing, copying, or + # using the SOFTWARE, you agree to be bound by the terms of that + # LICENSE. + # Phil Shafer, July 2014 + # + +.. default-role:: code + +libxo - A Library for Generating Text, XML, JSON, and HTML Output +=================================================================== + +The libxo library allows an application to generate text, XML, JSON, +and HTML output, suitable for both command line use and for web +applications. The application decides at run time which output style +should be produced. By using libxo, a single source code path can +emit multiple styles of output using command line options to select +the style, along with optional behaviors. libxo includes support for +multiple output streams, pluralization, color, syslog, +:manpage:`humanized(3)` output, internationalization, and UTF-8. The +library aims to minimize the cost of migrating code to libxo. + +libxo ships as part of FreeBSD. + +.. toctree:: + :maxdepth: 3 + :caption: Documentation Contents: + + intro + getting + formatting + options + format-strings + field-roles + field-modifiers + field-formatting + api + xo + xolint + xohtml + xopo + faq + howto + example + +Indices and tables +================== + +* :ref:`genindex` +* :ref:`search` diff --git a/doc/intro.rst b/doc/intro.rst new file mode 100644 index 000000000000..40b3a4f4a5de --- /dev/null +++ b/doc/intro.rst @@ -0,0 +1,90 @@ + +Introducing libxo +================= + +The libxo library allows an application to generate text, XML, JSON, +and HTML output using a common set of function calls. The application +decides at run time which output style should be produced. The +application calls a function "xo_emit" to product output that is +described in a format string. A "field descriptor" tells libxo what +the field is and what it means. Each field descriptor is placed in +braces with printf-like :ref:`format-strings`:: + + xo_emit(" {:lines/%7ju} {:words/%7ju} " + "{:characters/%7ju} {d:filename/%s}\n", + linect, wordct, charct, file); + +Each field can have a role, with the 'value' role being the default, +and the role tells libxo how and when to render that field (see +:ref:`field-roles` for details). Modifiers change how the field is +rendered in different output styles (see :ref:`field-modifiers` for +details. Output can then be generated in various style, using the +"--libxo" option:: + + % wc /etc/motd + 25 165 1140 /etc/motd + % wc --libxo xml,pretty,warn /etc/motd + + + 25 + 165 + 1140 + /etc/motd + + + % wc --libxo json,pretty,warn /etc/motd + { + "wc": { + "file": [ + { + "lines": 25, + "words": 165, + "characters": 1140, + "filename": "/etc/motd" + } + ] + } + } + % wc --libxo html,pretty,warn /etc/motd +
+
+
25
+
+
165
+
+
1140
+
+
/etc/motd
+
+ +Same code path, same format strings, same information, but it's +rendered in distinct styles based on run-time flags. + +.. admonition:: Tale of Two Code Paths + + You want to prepare for the future, but you need to live in the + present. You'd love a flying car, but need to get work done today. + You want to support features like XML, JSON, and HTML rendering to + allow integration with NETCONF, REST, and web browsers, but you need + to make text output for command line users. + + And you don't want multiple code paths that can't help but get out + of sync:: + + /* None of this "if (xml) {... } else {...}" logic */ + if (xml) { + /* some code to make xml */ + } else { + /* other code to make text */ + /* oops! forgot to add something on both clauses! */ + } + + /* And ifdefs are right out. */ + #ifdef MAKE_XML + /* icky */ + #else + /* pooh */ + #endif + + But you'd really, really like all the fancy features that modern + encoding formats can provide. libxo can help. diff --git a/doc/libxo-manual.html b/doc/libxo-manual.html index b56ddabbab89..a10e056b4954 100644 --- a/doc/libxo-manual.html +++ b/doc/libxo-manual.html @@ -515,7 +515,7 @@ li.indline1 { } @top-right { - content: "August 2017"; + content: "May 2018"; } @top-center { @@ -22011,7 +22011,7 @@ jQuery(function ($) { -August 3, 2017 +May 21, 2018

libxo: The Easy Way to Generate text, XML, JSON, and HTML output
libxo-manual

@@ -22676,13 +22676,13 @@ jQuery(function ($) { #else /* pooh */ #endif -

But you'd really, really like all the fancy features that modern encoding formats can provide. libxo can help.

+

But you'd really, really like all the fancy features that modern encoding formats can provide. libxo can help.

The libxo library allows an application to generate text, XML, JSON, and HTML output using a common set of function calls. The application decides at run time which output style should be produced. The application calls a function "xo_emit" to product output that is described in a format string. A "field descriptor" tells libxo what the field is and what it means. Each field descriptor is placed in braces with a printf-like format string (Section 3.2):

     xo_emit(" {:lines/%7ju} {:words/%7ju} "
             "{:characters/%7ju} {d:filename/%s}\n",
             linect, wordct, charct, file);
-

Each field can have a role, with the 'value' role being the default, and the role tells libxo how and when to render that field (see Section 3.2.1 for details). Modifiers change how the field is rendered in different output styles (see Section 3.2.2 for details. Output can then be generated in various style, using the "‑‑libxo" option:

+

Each field can have a role, with the 'value' role being the default, and the role tells libxo how and when to render that field (see Section 3.2.1 for details). Modifiers change how the field is rendered in different output styles (see Section 3.2.2 for details. Output can then be generated in various style, using the "‑‑libxo" option:

     % wc /etc/motd
           25     165    1140 /etc/motd
@@ -22719,7 +22719,7 @@ jQuery(function ($) {
       <div class="text"> </div>
       <div class="data" data-tag="filename">/etc/motd</div>
     </div>
-

Same code path, same format strings, same information, but it's rendered in distinct styles based on run-time flags.

+

Same code path, same format strings, same information, but it's rendered in distinct styles based on run-time flags.

@@ -22736,7 +22736,7 @@ jQuery(function ($) {

We are following the branching scheme from http://nvie.com/posts/a-successful-git-branching-model/ which means we will do development under the "develop" branch, and release from the "master" branch. To clone a developer tree, run the following command:

   git clone https://github.com/Juniper/libxo.git -b develop
-

We're using semantic release numbering, as defined in http://semver.org/spec/v2.0.0.html.

+

We're using semantic release numbering, as defined in http://semver.org/spec/v2.0.0.html.

libxo is open source, distributed under the BSD license. It shipped as part of the FreeBSD operating system starting with release 11.0.

Issues, problems, and bugs should be directly to the issues page on our github site.

Section Contents:

@@ -22756,12 +22756,12 @@ jQuery(function ($) { 
     tar -zxf libxo-RELEASE.tar.gz
     cd libxo-RELEASE
-

[Note: for Solaris users, your "tar" command lacks the "‑z" flag, so you'll need to substitute "gzip -dc "file" | tar xf -" instead of "tar -zxf "file"".]

+

[Note: for Solaris users, your "tar" command lacks the "‑z" flag, so you'll need to substitute "gzip -dc "file" | tar xf -" instead of "tar -zxf "file"".]

B) Use the current build from github. This gives you the most recent source code, which might be less stable than a specific release. To build libxo from the git repo:

     git clone https://github.com/Juniper/libxo.git
     cd libxo
-

_BE AWARE_: The github repository does _not_ contain the files generated by "autoreconf", with the notable exception of the "m4" directory. Since these files (depcomp, configure, missing, install-sh, etc) are generated files, we keep them out of the source code repository.

+

_BE AWARE_: The github repository does _not_ contain the files generated by "autoreconf", with the notable exception of the "m4" directory. Since these files (depcomp, configure, missing, install-sh, etc) are generated files, we keep them out of the source code repository.

This means that if you download the a release distfile, these files will be ready and you'll just need to run "configure", but if you download the source code from svn, then you'll need to run "autoreconf" by hand. This step is done for you by the "setup.sh" script, described in the next section.

@@ -22779,7 +22779,7 @@ jQuery(function ($) { make make test sudo make install -

The following sections will walk through each of these steps with additional details and options, but the above directions should be all that's needed.

+

The following sections will walk through each of these steps with additional details and options, but the above directions should be all that's needed.

Section Contents:

  • Section 2.2.1
    • @@ -22796,7 +22796,7 @@ jQuery(function ($) {

    Run the "setup.sh" script to set up the build. This script runs the "autoreconf" command to generate the "configure" script and other generated files.

         sh bin/setup.sh
-

    Note: We're are currently using autoreconf version 2.69.

    +

    Note: We're are currently using autoreconf version 2.69.

@@ -22810,15 +22810,15 @@ jQuery(function ($) { 
     cd build
     ../configure
-

Expect to see the "configure" script generate the following error:

+

Expect to see the "configure" script generate the following error:

     /usr/bin/rm: cannot remove `libtoolT': No such file or directory
-

This error is harmless and can be safely ignored.

+

This error is harmless and can be safely ignored.

By default, libxo installs architecture-independent files, including extension library files, in the /usr/local directories. To specify an installation prefix other than /usr/local for all installation files, include the --prefix=prefix option and specify an alternate location. To install just the extension library files in a different, user-defined location, include the --with-extensions-dir=dir option and specify the location where the extension libraries will live.

     cd build
     ../configure [OPTION]... [VAR=VALUE]...
-

Section Contents:

+

Section Contents:

  • Section 2.2.2.1
  • Section 2.2.2.2
    • @@ -22832,7 +22832,7 @@ jQuery(function ($) {

    Once the "configure" script is run, build the images using the "make" command:

         make
-

+

@@ -22842,7 +22842,7 @@ jQuery(function ($) {

libxo includes a set of regression tests that can be run to ensure the software is working properly. These test are optional, but will help determine if there are any issues running libxo on your machine. To run the regression tests:

     make test
-
+

@@ -22853,15 +22853,15 @@ jQuery(function ($) {

Once the software is built, you'll need to install libxo using the "make install" command. If you are the root user, or the owner of the installation directory, simply issue the command:

     make install
-

If you are not the "root" user and are using the "sudo" package, use:

+

If you are not the "root" user and are using the "sudo" package, use:

     sudo make install
-

Verify the installation by viewing the output of "xo --version":

+

Verify the installation by viewing the output of "xo --version":

     % xo --version
     libxo version 0.3.5-git-develop
     xo version 0.3.5-git-develop
-

+
@@ -22897,7 +22897,7 @@ jQuery(function ($) { data-xpath="/top/domain">example.com</div> <div class="text">...</div> </div> -

Section Contents:

+

Section Contents:

  • Section 3.1
  • Section 3.2
    • @@ -22936,14 +22936,14 @@ jQuery(function ($) { 36 ./src 40 ./bin 90 . -

    In this example (taken from du source code), the code to generate this data might look like:

    +

    In this example (taken from du source code), the code to generate this data might look like:

         printf("%d\t%s\n", num_blocks, path);
-

    Simple, direct, obvious. But it's only making text output. Imagine using a single code path to make TEXT, XML, JSON or HTML, deciding at run time which to generate.

    +

    Simple, direct, obvious. But it's only making text output. Imagine using a single code path to make TEXT, XML, JSON or HTML, deciding at run time which to generate.

    libxo expands on the idea of printf format strings to make a single format containing instructions for creating multiple output styles:

         xo_emit("{:blocks/%d}\t{:path/%s}\n", num_blocks, path);
-

    This line will generate the same text output as the earlier printf call, but also has enough information to generate XML, JSON, and HTML.

    +

    This line will generate the same text output as the earlier printf call, but also has enough information to generate XML, JSON, and HTML.

    The following sections introduce the other formats.

    @@ -22966,7 +22966,7 @@ jQuery(function ($) { <blocks>90</blocks> <path>.</path> </item> -

    XML is a W3C standard for encoding data. See w3c.org/TR/xml for additional information.

    +

    XML is a W3C standard for encoding data. See w3c.org/TR/xml for additional information.

    @@ -22981,7 +22981,7 @@ jQuery(function ($) { { "blocks": 40, "path" : "./bin" }, { "blocks": 90, "path" : "./" } ] -

    +

    @@ -23006,7 +23006,7 @@ jQuery(function ($) { <div class="padding"> </div> <div class="data" data-tag="path">./</div> </div> -
    +

    @@ -23019,15 +23019,15 @@ jQuery(function ($) { 
         '{' [ role | modifier ]* [',' long-names ]* ':' [ content ]
             [ '/' field-format [ '/' encoding-format ]] '}'
-

    The role describes the function of the field, while the modifiers enable optional behaviors. The contents, field-format, and encoding-format are used in varying ways, based on the role. These are described in the following sections.

    +

    The role describes the function of the field, while the modifiers enable optional behaviors. The contents, field-format, and encoding-format are used in varying ways, based on the role. These are described in the following sections.

    In the following example, three field descriptors appear. The first is a padding field containing three spaces of padding, the second is a label ("In stock"), and the third is a value field ("in‑stock"). The in-stock field has a "%u" format that will parse the next argument passed to the xo_emit function as an unsigned integer.

         xo_emit("{P:   }{Lwc:In stock}{:in-stock/%u}\n", 65);
-

    This single line of code can generate text (" In stock: 65\n"), XML ("<in‑stock>65</in‑stock>"), JSON ('"in‑stock": 6'), or HTML (too lengthy to be listed here).

    +

    This single line of code can generate text (" In stock: 65\n"), XML ("<in‑stock>65</in‑stock>"), JSON ('"in‑stock": 6'), or HTML (too lengthy to be listed here).

    While roles and modifiers typically use single character for brevity, there are alternative names for each which allow more verbose formatting strings. These names must be preceded by a comma, and may follow any single-character values:

         xo_emit("{L,white,colon:In stock}{,key:in-stock/%u}\n", 65);
-

    Section Contents:

    +

    Section Contents:

    • Section 3.2.1
    • Section 3.2.2
      • @@ -23127,14 +23127,14 @@ jQuery(function ($) { EXAMPLE: xo_emit("{L:Free}{D::}{P: }{:free/%u} {U:Blocks}\n", free_blocks); -

      When a role is not provided, the "value" role is used as the default.

      +

      When a role is not provided, the "value" role is used as the default.

      Roles and modifiers can also use more verbose names, when preceded by a comma:

           EXAMPLE:
         xo_emit("{,label:Free}{,decoration::}{,padding:   }"
                 "{,value:free/%u} {,units:Blocks}\n",
                 free_blocks);
-

      Section Contents:

      +

      Section Contents:

      • Section 3.2.1.1
      • Section 3.2.1.2
        • @@ -23156,24 +23156,24 @@ jQuery(function ($) {

        Colors and effects control how text values are displayed; they are used for display styles (TEXT and HTML).

             xo_emit("{C:bold}{:value}{C:no-bold}\n", value);
-

        Colors and effects remain in effect until modified by other "C"-role fields.

        +

        Colors and effects remain in effect until modified by other "C"-role fields.

             xo_emit("{C:bold}{C:inverse}both{C:no-bold}only inverse\n");
-

        If the content is empty, the "reset" action is performed.

        +

        If the content is empty, the "reset" action is performed.

             xo_emit("{C:both,underline}{:value}{C:}\n", value);
-

        The content should be a comma-separated list of zero or more colors or display effects.

        +

        The content should be a comma-separated list of zero or more colors or display effects.

             xo_emit("{C:bold,inverse}Ugly{C:no-bold,no-inverse}\n");
-

        The color content can be either static, when placed directly within the field descriptor, or a printf-style format descriptor can be used, if preceded by a slash ("/"):

        +

        The color content can be either static, when placed directly within the field descriptor, or a printf-style format descriptor can be used, if preceded by a slash ("/"):

            xo_emit("{C:/%s%s}{:value}{C:}", need_bold ? "bold" : "",
            need_underline ? "underline" : "", value);
-

        Color names are prefixed with either "fg‑" or "bg‑" to change the foreground and background colors, respectively.

        +

        Color names are prefixed with either "fg‑" or "bg‑" to change the foreground and background colors, respectively.

             xo_emit("{C:/fg-%s,bg-%s}{Lwc:Cost}{:cost/%u}{C:reset}\n",
             fg_color, bg_color, cost);
-

        The following table lists the supported effects:

        +

        The following table lists the supported effects:

        @@ -23278,7 +23278,7 @@ jQuery(function ($) {

        Decorations are typically punctuation marks such as colons, semi-colons, and commas used to decorate the text and make it simpler for human readers. By marking these distinctly, HTML usage scenarios can use CSS to direct their display parameters.

             xo_emit("{D:((}{:name}{D:))}\n", name);
-
        +

        @@ -23290,10 +23290,10 @@ jQuery(function ($) {

        The simplified version can be generated for a single message using the "xopo -s <text>" command, or an entire .pot can be translated using the "xopo -f <input> -o <output>" command.

            xo_emit("{G:}Invalid token\n");
-

        The {G:} role allows a domain name to be set. gettext calls will continue to use that domain name until the current format string processing is complete, enabling a library function to emit strings using it's own catalog. The domain name can be either static as the content of the field, or a format can be used to get the domain name from the arguments.

        +

        The {G:} role allows a domain name to be set. gettext calls will continue to use that domain name until the current format string processing is complete, enabling a library function to emit strings using it's own catalog. The domain name can be either static as the content of the field, or a format can be used to get the domain name from the arguments.

            xo_emit("{G:libc}Service unavailable in restricted mode\n");
-

        See Section 11.5 for additional details.

        +

        See Section 11.5 for additional details.

        @@ -23304,7 +23304,7 @@ jQuery(function ($) {

        Labels are text that appears before a value.

             xo_emit("{Lwc:Cost}{:cost/%u}\n", cost);
-

        +

        @@ -23314,7 +23314,7 @@ jQuery(function ($) {

        Notes are text that appears after a value.

             xo_emit("{:cost/%u} {N:per year}\n", cost);
-
        +

        @@ -23326,7 +23326,7 @@ jQuery(function ($) { 
             xo_emit("{P:        }{Lwc:Cost}{:cost/%u}\n", cost);
     xo_emit("{P:/%30s}{Lwc:Cost}{:cost/%u}\n", "", cost);
-
        +

        @@ -23337,10 +23337,10 @@ jQuery(function ($) { 
             xo_emit("{T:Interface Statistics}\n");
     xo_emit("{T:/%20.20s}{T:/%6.6s}\n", "Item Name", "Cost");
-

        Title fields have an extra convenience feature; if both content and format are specified, instead of looking to the argument list for a value, the content is used, allowing a mixture of format and content within the field descriptor:

        +

        Title fields have an extra convenience feature; if both content and format are specified, instead of looking to the argument list for a value, the content is used, allowing a mixture of format and content within the field descriptor:

             xo_emit("{T:Name/%20s}{T:Count/%6s}\n");
-

        Since the incoming argument is a string, the format must be "%s" or something suitable.

        +

        Since the incoming argument is a string, the format must be "%s" or something suitable.

        @@ -23351,15 +23351,15 @@ jQuery(function ($) {

        Units are the dimension by which values are measured, such as degrees, miles, bytes, and decibels. The units field carries this information for the previous value field.

             xo_emit("{Lwc:Distance}{:distance/%u}{Uw:miles}\n", miles);
-

        Note that the sense of the 'w' modifier is reversed for units; a blank is added before the contents, rather than after it.

        +

        Note that the sense of the 'w' modifier is reversed for units; a blank is added before the contents, rather than after it.

        When the XOF_UNITS flag is set, units are rendered in XML as the "units" attribute:

             <distance units="miles">50</distance>
-

        Units can also be rendered in HTML as the "data‑units" attribute:

        +

        Units can also be rendered in HTML as the "data‑units" attribute:

             <div class="data" data-tag="distance" data-units="miles"
          data-xpath="/top/data/distance">50</div>
-

        +

        @@ -23372,7 +23372,7 @@ jQuery(function ($) { length, width, height); xo_emit("{:author} wrote \"{:poem}\" in {:year/%4d}\n, author, poem, year); -
        +

        @@ -23383,10 +23383,10 @@ jQuery(function ($) {

        To give a width directly, encode it as the content of the anchor tag:

             xo_emit("({[:10}{:min/%d}/{:max/%d}{]:})\n", min, max);
-

        To pass a width as an argument, use "%d" as the format, which must appear after the "/". Note that only "%d" is supported for widths. Using any other value could ruin your day.

        +

        To pass a width as an argument, use "%d" as the format, which must appear after the "/". Note that only "%d" is supported for widths. Using any other value could ruin your day.

             xo_emit("({[:/%d}{:min/%d}/{:max/%d}{]:})\n", width, min, max);
-

        If the width is negative, padding will be added on the right, suitable for left justification. Otherwise the padding will be added to the left of the fields between the start and stop anchors, suitable for right justification. If the width is zero, nothing happens. If the number of columns of output between the start and stop anchors is less than the absolute value of the given width, nothing happens.

        +

        If the width is negative, padding will be added on the right, suitable for left justification. Otherwise the padding will be added to the left of the fields between the start and stop anchors, suitable for right justification. If the width is zero, nothing happens. If the number of columns of output between the start and stop anchors is less than the absolute value of the given width, nothing happens.

        Widths over 8k are considered probable errors and not supported. If XOF_WARN is set, a warning will be generated.

        @@ -23519,7 +23519,7 @@ jQuery(function ($) { "label": "value" XML: <label>value</label> -

        The argument modifier allows field names for value fields to be passed on the stack, avoiding the need to build a field descriptor using snprintf. For many field roles, the argument modifier is not needed, since those roles have specific mechanisms for arguments, such as "{C:fg‑%s}".

        +

        The argument modifier allows field names for value fields to be passed on the stack, avoiding the need to build a field descriptor using snprintf. For many field roles, the argument modifier is not needed, since those roles have specific mechanisms for arguments, such as "{C:fg‑%s}".

        @@ -23533,7 +23533,7 @@ jQuery(function ($) { xo_emit("{Lc:Name}{:name}\n", "phil"); TEXT: Name:phil -

        The colon modifier is only used for the TEXT and HTML output styles. It is commonly combined with the space modifier ('{w:}'). It is purely a convenience feature.

        +

        The colon modifier is only used for the TEXT and HTML output styles. It is commonly combined with the space modifier ('{w:}'). It is purely a convenience feature.

        @@ -23549,7 +23549,7 @@ jQuery(function ($) { Name: phil 1 XML: <id>1</id> -

        The display modifier is the opposite of the encoding modifier, and they are often used to give to distinct views of the underlying data.

        +

        The display modifier is the opposite of the encoding modifier, and they are often used to give to distinct views of the underlying data.

        @@ -23565,7 +23565,7 @@ jQuery(function ($) { Name: phil XML: <name>phil</name><id>1</id> -

        The encoding modifier is the opposite of the display modifier, and they are often used to give to distinct views of the underlying data.

        +

        The encoding modifier is the opposite of the display modifier, and they are often used to give to distinct views of the underlying data.

        @@ -23577,7 +23577,7 @@ jQuery(function ($) {

        In the following example, the strings "State" and "full" are passed to gettext() to find locale-based translated strings.

             xo_emit("{Lgwc:State}{g:state}\n", "full");
-

        See Section 3.2.1.3, Section 3.2.2.10, and Section 11.5 for additional details.

        +

        See Section 3.2.1.3, Section 3.2.2.10, and Section 11.5 for additional details.

        @@ -23597,11 +23597,11 @@ jQuery(function ($) { input, output, errors, capacity, remaining); TEXT: 21, 57 K, 96M, 44M, 1.2G -

        In the HTML style, the original numeric value is rendered in the "data‑number" attribute on the <div> element:

        +

        In the HTML style, the original numeric value is rendered in the "data‑number" attribute on the <div> element:

             <div class="data" data-tag="errors"
          data-number="100663296">96M</div>
-

        +

        @@ -23619,7 +23619,7 @@ jQuery(function ($) { xo_close_instance("user"); } xo_close_list("user"); -

        Currently the key modifier is only used when generating XPath value for the HTML output style when XOF_XPATH is set, but other uses are likely in the near future.

        +

        Currently the key modifier is only used when generating XPath value for the HTML output style when XOF_XPATH is set, but other uses are likely in the near future.

        @@ -23638,7 +23638,7 @@ jQuery(function ($) { <user>pallavi</user> JSON: "user": [ "phil", "pallavi" ] -

        The name of the field must match the name of the leaf list.

        +

        The name of the field must match the name of the leaf list.

        @@ -23653,7 +23653,7 @@ jQuery(function ($) { xo_emit("{n:fancy/%s}", bool); JSON: "fancy": true -

        +

        @@ -23663,7 +23663,7 @@ jQuery(function ($) {

        The plural modifier selects the appropriate plural form of an expression based on the most recent number emitted and the current language settings. The contents of the field should be the singular and plural English values, separated by a comma:

             xo_emit("{:bytes} {Ngp:byte,bytes}\n", bytes);
-

        The plural modifier is meant to work with the gettext modifier ({g:}) but can work independently. See Section 3.2.2.5.

        +

        The plural modifier is meant to work with the gettext modifier ({g:}) but can work independently. See Section 3.2.2.5.

        When used without the gettext modifier or when the message does not appear in the message catalog, the first token is chosen when the last numeric value is equal to 1; otherwise the second value is used, mimicking the simple pluralization rules of English.

        When used with the gettext modifier, the ngettext(3) function is called to handle the heavy lifting, using the message catalog to convert the singular and plural forms into the native language.

        @@ -23679,10 +23679,10 @@ jQuery(function ($) { xo_emit("{q:time/%d}", 2014); JSON: "year": "2014" -

        The heuristic is based on the format; if the format uses any of the following conversion specifiers, then no quotes are used:

        +

        The heuristic is based on the format; if the format uses any of the following conversion specifiers, then no quotes are used:

             d i o u x X D O U e E f F g G a A c C p
-

        +

        @@ -23695,7 +23695,7 @@ jQuery(function ($) { xo_emit("{t:description}", " some input "); JSON: "description": "some input" -
        +

        @@ -23708,7 +23708,7 @@ jQuery(function ($) { xo_emit("{Lw:Name}{:name}\n", "phil"); TEXT: Name phil -

        The white space modifier is only used for the TEXT and HTML output styles. It is commonly combined with the colon modifier ('{c:}'). It is purely a convenience feature.

        +

        The white space modifier is only used for the TEXT and HTML output styles. It is commonly combined with the colon modifier ('{c:}'). It is purely a convenience feature.

        Note that the sense of the 'w' modifier is reversed for the units role ({Uw:}); a blank is added before the contents, rather than after it.

        @@ -23724,7 +23724,7 @@ jQuery(function ($) {

        The format string has the form:

           '%' format-modifier * format-character
-

        The format- modifier can be:

        +

        The format- modifier can be:

        • a '#' character, indicating the output value should be prefixed with '0x', typically to indicate a base 16 (hex) value.
          • @@ -23923,7 +23923,7 @@ jQuery(function ($) { 
              xo_emit("All strings are utf-8 content {:tag/%ls}",
            L"except for wide strings");
-

          "%S" is equivalent to "%ls".

          +

          "%S" is equivalent to "%ls".

        Name
        @@ -23973,12 +23973,12 @@ jQuery(function ($) { xo_emit("It was ordered on {:order-time/%ls}.\n", when); } -

        It is important to note that xo_emit will perform the conversion required to make appropriate output. Text style output uses the current locale (as described above), while XML, JSON, and HTML use UTF-8.

        +

        It is important to note that xo_emit will perform the conversion required to make appropriate output. Text style output uses the current locale (as described above), while XML, JSON, and HTML use UTF-8.

        UTF-8 and locale-encoded strings can use multiple bytes to encode one column of data. The traditional "precision'" (aka "max‑width") value for "%s" printf formatting becomes overloaded since it specifies both the number of bytes that can be safely referenced and the maximum number of columns to emit. xo_emit uses the precision as the former, and adds a third value for specifying the maximum number of columns.

        In this example, the name field is printed with a minimum of 3 columns and a maximum of 6. Up to ten bytes of data at the location given by 'name' are in used in filling those columns.

             xo_emit("{:name/%3.10.6s}", name);
-
        +

        @@ -23999,7 +23999,7 @@ jQuery(function ($) { <div class="text">The hat is </div> <div class="data" data-tag="size">extra small</div> <div class="text">.</div> -
        +

        @@ -24011,7 +24011,7 @@ jQuery(function ($) { xo_emit("{:filename} cannot be opened: {:error/%m}", filename); xo_emit("{:filename} cannot be opened: {:error/%s}", filename, strerror(errno)); -
        +

        @@ -24120,7 +24120,7 @@ jQuery(function ($) { EXAMPLE: xo_emit_f(XOEF_RETAIN, "{:some/%02d}{:thing/%-6s}{:fancy}\n", some, thing, fancy); -

        To retain parsed format information, use the XOEF_RETAIN flag to the xo_emit_f() function. A complete set of xo_emit_f functions exist to match all the xo_emit function signatures (with handles, varadic argument, and printf-like flags):

        +

        To retain parsed format information, use the XOEF_RETAIN flag to the xo_emit_f() function. A complete set of xo_emit_f functions exist to match all the xo_emit function signatures (with handles, varadic argument, and printf-like flags):

        Format
        @@ -24162,7 +24162,7 @@ jQuery(function ($) { xo_emit_f(XOEF_RETAIN, fmt, name[i], count[i]); } xo_retain_clear(fmt); -

        The retained information is kept as thread-specific data.

        +

        The retained information is kept as thread-specific data.

        @@ -24174,7 +24174,7 @@ jQuery(function ($) { 
                 xo_emit("{P:   }{Lwc:In stock}{:in-stock/%u}\n",
                 instock);
-

        This call will generate the following output:

        +

        This call will generate the following output:

           TEXT: 
        In stock: 144
@@ -24190,13 +24190,13 @@ jQuery(function ($) {
         <div class="padding"> </div>
         <div class="data" data-tag="in-stock">144</div>
       </div>
-

        Clearly HTML wins the verbosity award, and this output does not include XOF_XPATH or XOF_INFO data, which would expand the penultimate line to:

        +

        Clearly HTML wins the verbosity award, and this output does not include XOF_XPATH or XOF_INFO data, which would expand the penultimate line to:

                <div class="data" data-tag="in-stock"
           data-xpath="/top/data/item/in-stock"
           data-type="number"
           data-help="Number of items in stock">144</div>
-

        +

        @@ -24210,10 +24210,10 @@ jQuery(function ($) { <user>phil</user> <user>pallavi</user> <user>sjg</user> -

        JSON encodes lists using a single name and square brackets:

        +

        JSON encodes lists using a single name and square brackets:

             "user": [ "phil", "pallavi", "sjg" ]
-

        This means libxo needs three distinct indications of hierarchy: one for containers of hierarchy appear only once for any specific parent, one for lists, and one for each item in a list.

        +

        This means libxo needs three distinct indications of hierarchy: one for containers of hierarchy appear only once for any specific parent, one for lists, and one for each item in a list.

        Section Contents:

        • Section 3.3.1
          • @@ -24232,11 +24232,11 @@ jQuery(function ($) { 
               int xo_open_container_h (xo_handle_t *xop, const char *name);
     int xo_open_container (const char *name);
-

          To close a level, use the xo_close_container() or xo_close_container_h() functions:

          +

          To close a level, use the xo_close_container() or xo_close_container_h() functions:

               int xo_close_container_h (xo_handle_t *xop, const char *name);
     int xo_close_container (const char *name);
-

          Each open call must have a matching close call. If the XOF_WARN flag is set and the name given does not match the name of the currently open container, a warning will be generated.

          +

          Each open call must have a matching close call. If the XOF_WARN flag is set and the name given does not match the name of the currently open container, a warning will be generated.

               Example:
 
@@ -24265,7 +24265,7 @@ jQuery(function ($) {
       HTML:
         <div class="data"
              data-tag="host-name">my-host.example.org</div>
-

        +

        @@ -24283,7 +24283,7 @@ jQuery(function ($) { } xo_close_list("item"); -

        Getting the list and instance calls correct is critical to the proper generation of XML and JSON data.

        +

        Getting the list and instance calls correct is critical to the proper generation of XML and JSON data.

        @@ -24294,12 +24294,12 @@ jQuery(function ($) {

        Some users may find tracking the names of open containers, lists, and instances inconvenient. libxo offers a "Do The Right Thing" mode, where libxo will track the names of open containers, lists, and instances so the close function can be called without a name. To enable DTRT mode, turn on the XOF_DTRT flag prior to making any other libxo output.

             xo_set_flags(NULL, XOF_DTRT);
-

        Each open and close function has a version with the suffix "_d", which will close the open container, list, or instance:

        +

        Each open and close function has a version with the suffix "_d", which will close the open container, list, or instance:

             xo_open_container("top");
     ...
     xo_close_container_d();
-

        This also works for lists and instances:

        +

        This also works for lists and instances:

             xo_open_list("item");
     for (...) {
@@ -24308,7 +24308,7 @@ jQuery(function ($) {
         xo_close_instance_d();
     }
     xo_close_list_d();
-

        Note that the XOF_WARN flag will also cause libxo to track open containers, lists, and instances. A warning is generated when the name given to the close function and the name recorded do not match.

        +

        Note that the XOF_WARN flag will also cause libxo to track open containers, lists, and instances. A warning is generated when the name given to the close function and the name recorded do not match.

        @@ -24326,7 +24326,7 @@ jQuery(function ($) { dump_fish_details(i); xo_close_marker("fish-guts"); } -

        +

        @@ -24348,7 +24348,7 @@ jQuery(function ($) { my-app --libxo warn,pretty arg1 my-app --libxo=warn,pretty arg1 my-app --libxo:WP arg1 -

        Programs using libxo are expecting to call the xo_parse_args function to parse these arguments. See Section 5.4.1 for details.

        +

        Programs using libxo are expecting to call the xo_parse_args function to parse these arguments. See Section 5.4.1 for details.

        Section Contents:

        • Section 4.1
          • @@ -24587,17 +24587,17 @@ jQuery(function ($) {

          For example consider the following xo_emit call:

               xo_emit("{C:fg-red,bg-green}Merry XMas!!{C:}\n");
-

          To turn all colored output to red-on-blue, use eight pairs of "red/blue" mappings separated by "+"s:

          +

          To turn all colored output to red-on-blue, use eight pairs of "red/blue" mappings separated by "+"s:

               --libxo colors=red/blue+red/blue+red/blue+red/blue+\
                    red/blue+red/blue+red/blue+red/blue
-

          To turn the red-on-green text to magenta-on-cyan, give a "magenta" foreground value for red (the second mapping) and a "cyan" background to green (the third mapping):

          +

          To turn the red-on-green text to magenta-on-cyan, give a "magenta" foreground value for red (the second mapping) and a "cyan" background to green (the third mapping):

               --libxo colors=+magenta+/cyan
-

          Consider the common situation where blue output looks unreadable on a terminal session with a black background. To turn both "blue" foreground and background output to "yellow", give only the fifth mapping, skipping the first four mappings with bare "+"s:

          +

          Consider the common situation where blue output looks unreadable on a terminal session with a black background. To turn both "blue" foreground and background output to "yellow", give only the fifth mapping, skipping the first four mappings with bare "+"s:

               --libxo colors=++++yellow/yellow
-
          +
          @@ -24631,7 +24631,7 @@ jQuery(function ($) { 
               xo_emit("test");
     xo_emit_h(NULL, "test");
-

          Handles are created using xo_create() and destroy using xo_destroy().

          +

          Handles are created using xo_create() and destroy using xo_destroy().

          Section Contents:

          @@ -24668,7 +24668,7 @@ jQuery(function ($) { 
               xo_handle_t *xo_create_to_file (FILE *fp, unsigned style,
                                     unsigned flags);
-

          Use the XOF_CLOSE_FP flag to trigger a call to fclose() for the FILE pointer when the handle is destroyed.

          +

          Use the XOF_CLOSE_FP flag to trigger a call to fclose() for the FILE pointer when the handle is destroyed.

          @@ -24682,7 +24682,7 @@ jQuery(function ($) { xo_write_func_t write_func, xo_close_func_t close_func); xo_flush_func_t flush_func); -

          +

          @@ -24692,10 +24692,10 @@ jQuery(function ($) {

          To set the style, use the xo_set_style() function:

               void xo_set_style(xo_handle_t *xop, unsigned style);
-

          To use the default handle, pass a NULL handle:

          +

          To use the default handle, pass a NULL handle:

               xo_set_style(NULL, XO_STYLE_XML);
-
          +

          @@ -24705,10 +24705,10 @@ jQuery(function ($) {

          To find the current style, use the xo_get_style() function:

               xo_style_t xo_get_style(xo_handle_t *xop);
-

          To use the default handle, pass a NULL handle:

          +

          To use the default handle, pass a NULL handle:

               style = xo_get_style(NULL);
-

          Section Contents:

          +

          Section Contents:

          • Section 5.1.5.1
          • Section 5.1.5.2
            • @@ -24754,11 +24754,11 @@ jQuery(function ($) {

            The xo_set_style_name() can be used to set the style based on a name encoded as a string:

                 int xo_set_style_name (xo_handle_t *xop, const char *style);
-

            The name can be any of the styles: "text", "xml", "json", or "html".

            +

            The name can be any of the styles: "text", "xml", "json", or "html".

                 EXAMPLE:
         xo_set_style_name(NULL, "html");
-
          +

          @@ -24769,10 +24769,10 @@ jQuery(function ($) {

          To set the flags, use the xo_set_flags() function:

               void xo_set_flags(xo_handle_t *xop, unsigned flags);
-

          To use the default handle, pass a NULL handle:

          +

          To use the default handle, pass a NULL handle:

               xo_set_style(NULL, XO_STYLE_XML);
-

          Section Contents:

          +

          Section Contents:

          +

          @@ -24908,7 +24908,7 @@ jQuery(function ($) {

          The xo_clear_flags() function turns off the given flags in a specific handle.

               void xo_clear_flags (xo_handle_t *xop, xo_xof_flags_t flags);
-
          +

          @@ -24918,7 +24918,7 @@ jQuery(function ($) {

          The xo_set_options() function accepts a comma-separated list of styles and flags and enables them for a specific handle.

               int xo_set_options (xo_handle_t *xop, const char *input);
-

          The options are identical to those listed in Section 4.

          +

          The options are identical to those listed in Section 4.

          @@ -24930,7 +24930,7 @@ jQuery(function ($) {

          The xo_destroy function releases a handle and any resources it is using. Calling xo_destroy with a NULL handle will release any resources associated with the default handle.

               void xo_destroy(xo_handle_t *xop);
-
          +

          @@ -24943,7 +24943,7 @@ jQuery(function ($) { int xo_emit (const char *fmt, ...); int xo_emit_h (xo_handle_t *xop, const char *fmt, ...); int xo_emit_hv (xo_handle_t *xop, const char *fmt, va_list vap); -

          The "fmt" argument is a string containing field descriptors as specified in Section 3.2. The use of a handle is optional and NULL can be passed to access the internal 'default' handle. See Section 5.1.

          +

          The "fmt" argument is a string containing field descriptors as specified in Section 3.2. The use of a handle is optional and NULL can be passed to access the internal 'default' handle. See Section 5.1.

          The remaining arguments to xo_emit() and xo_emit_h() are a set of arguments corresponding to the fields in the format string. Care must be taken to ensure the argument types match the fields in the format string, since an inappropriate cast can ruin your day. The vap argument to xo_emit_hv() points to a variable argument list that can be used to retrieve arguments via va_arg().

          Section Contents:

            @@ -24970,11 +24970,11 @@ jQuery(function ($) { int xo_emit_field (const char *rolmod, const char *contents, const char *fmt, const char *efmt, ...); -

            These functions are intended to avoid the scenario where one would otherwise need to compose a format descriptors using snprintf(). The individual parts of the format descriptor are passed in distinctly.

            +

            These functions are intended to avoid the scenario where one would otherwise need to compose a format descriptors using snprintf(). The individual parts of the format descriptor are passed in distinctly.

                 xo_emit("T", "Host name is ", NULL, NULL);
     xo_emit("V", "host-name", NULL, NULL, host-name);
-

          +

          @@ -24988,7 +24988,7 @@ jQuery(function ($) { const char *fmt, ...); int xo_attr_hv (xo_handle_t *xop, const char *name, const char *fmt, va_list vap); -

          The name parameter give the name of the attribute to be encoded. The fmt parameter gives a printf-style format string used to format the value of the attribute using any remaining arguments, or the vap parameter passed to xo_attr_hv().

          +

          The name parameter give the name of the attribute to be encoded. The fmt parameter gives a printf-style format string used to format the value of the attribute using any remaining arguments, or the vap parameter passed to xo_attr_hv().

               EXAMPLE:
       xo_attr("seconds", "%ld", (unsigned long) login_time);
@@ -24997,7 +24997,7 @@ jQuery(function ($) {
       xo_emit("Logged in at {:login-time}\n", buf);
     XML:
         <login-time seconds="1408336270">00:14</login-time>
-

          xo_attr is placed on the next container, instance, leaf, or leaf list that is emitted.

          +

          xo_attr is placed on the next container, instance, leaf, or leaf list that is emitted.

          Since attributes are only emitted in XML, their use should be limited to meta-data and additional or redundant representations of data already emitted in other form.

          @@ -25010,7 +25010,7 @@ jQuery(function ($) { 
               void xo_flush (void);
     void xo_flush_h (xo_handle_t *xop);
-

          Calling xo_flush also triggers the flush function associated with the handle. For the default handle, this is equivalent to "fflush(stdio);".

          +

          Calling xo_flush also triggers the flush function associated with the handle. For the default handle, this is equivalent to "fflush(stdio);".

          @@ -25023,7 +25023,7 @@ jQuery(function ($) { int xo_finish (void); int xo_finish_h (xo_handle_t *xop); void xo_finish_atexit (void); -

          Calling this function is vital to the proper operation of libxo, especially for the non-TEXT output styles.

          +

          Calling this function is vital to the proper operation of libxo, especially for the non-TEXT output styles.

          xo_finish_atexit is suitable for use with atexit(3).

          @@ -25045,7 +25045,7 @@ jQuery(function ($) { int xo_close_container_h (xo_handle_t *xop, const char *name); int xo_close_container_hd (xo_handle_t *xop); int xo_close_container_d (void); -

          The name parameter gives the name of the container, encoded in UTF-8. Since ASCII is a proper subset of UTF-8, traditional C strings can be used directly.

          +

          The name parameter gives the name of the container, encoded in UTF-8. Since ASCII is a proper subset of UTF-8, traditional C strings can be used directly.

          The close functions with the "_d" suffix are used in "Do The Right Thing" mode, where the name of the open containers, lists, and instances are maintained internally by libxo to allow the caller to avoid keeping track of the open container name.

          Use the XOF_WARN flag to generate a warning if the name given on the close does not match the current open container.

          For TEXT and HTML output, containers are not rendered into output text, though for HTML they are used when the XOF_XPATH flag is set.

          @@ -25056,7 +25056,7 @@ jQuery(function ($) { xo_close_container("system"); XML: <system><host-name>foo</host-name></system> -

          Section Contents:

          +

          Section Contents:

          @@ -25108,7 +25108,7 @@ jQuery(function ($) { "home": "/home/pallavi", } ] -

          +

          @@ -25139,7 +25139,7 @@ jQuery(function ($) { argc = xo_parse_args(argc, argv); if (argc < 0) exit(EXIT_FAILURE); -

          Following the call to xo_parse_args, the application can process the remaining arguments in a normal manner. See Section 4 for a description of valid arguments.

          +

          Following the call to xo_parse_args, the application can process the remaining arguments in a normal manner. See Section 4 for a description of valid arguments.

          @@ -25150,7 +25150,7 @@ jQuery(function ($) {

          The xo_set_program function sets name of the program as reported by functions like xo_failure, xo_warn, xo_err, etc. The program name is initialized by xo_parse_args, but subsequent calls to xo_set_program can override this value.

               xo_set_program(argv[0]);
-

          Note that the value is not copied, so the memory passed to xo_set_program (and xo_parse_args) must be maintained by the caller.

          +

          Note that the value is not copied, so the memory passed to xo_set_program (and xo_parse_args) must be maintained by the caller.

          @@ -25162,7 +25162,7 @@ jQuery(function ($) { 
                void xo_set_version (const char *version);
      void xo_set_version_h (xo_handle_t *xop, const char *version);
-

          +

          @@ -25180,7 +25180,7 @@ jQuery(function ($) { } xo_info_t; void xo_set_info (xo_handle_t *xop, xo_info_t *infop, int count); -

          Like other libxo calls, passing NULL for the handle tells libxo to use the default handle.

          +

          Like other libxo calls, passing NULL for the handle tells libxo to use the default handle.

          If the count is -1, libxo will count the elements of infop, but there must be an empty element at the end. More typically, the number is known to the application:

               xo_info_t info[] = {
@@ -25193,12 +25193,12 @@ jQuery(function ($) {
     int info_count = (sizeof(info) / sizeof(info[0]));
     ...
     xo_set_info(NULL, info, info_count);
-

          Third, the emission of info must be triggered with the XOF_INFO flag using either the xo_set_flags() function or the "‑‑libxo=info" command line argument.

          +

          Third, the emission of info must be triggered with the XOF_INFO flag using either the xo_set_flags() function or the "‑‑libxo=info" command line argument.

          The type and help values, if present, are emitted as the "data‑type" and "data‑help" attributes:

             <div class="data" data-tag="sku" data-type="string" 
        data-help="Stock Keeping Unit">GRO-000-533</div>
-
          +

          @@ -25209,7 +25209,7 @@ jQuery(function ($) { 
               void xo_set_allocator (xo_realloc_func_t realloc_func,
                            xo_free_func_t free_func);
-

          realloc_func should expect the same arguments as realloc(3) and return a pointer to memory following the same convention. free_func will receive the same argument as free(3) and should release it, as appropriate for the environment.

          +

          realloc_func should expect the same arguments as realloc(3) and return a pointer to memory following the same convention. free_func will receive the same argument as free(3) and should release it, as appropriate for the environment.

          By default, the standard realloc() and free() functions are used.

          @@ -25236,7 +25236,7 @@ jQuery(function ($) {

          For example, warnings can be enabled by:

               % env LIBXO_OPTIONS=warn my-app
-

          Since environment variables are inherited, child processes will have the same options, which may be undesirable, making the use of the "‑‑libxo" option is preferable in most situations.

          +

          Since environment variables are inherited, child processes will have the same options, which may be undesirable, making the use of the "‑‑libxo" option is preferable in most situations.

          @@ -25260,12 +25260,12 @@ jQuery(function ($) { const char *fmt, ...); void xo_message_hcv (xo_handle_t *xop, int code, const char *fmt, va_list vap); -

          These functions display the program name, a colon, a formatted message based on the arguments, and then optionally a colon and an error message associated with either "errno" or the "code" parameter.

          +

          These functions display the program name, a colon, a formatted message based on the arguments, and then optionally a colon and an error message associated with either "errno" or the "code" parameter.

               EXAMPLE:
         if (open(filename, O_RDONLY) < 0)
             xo_err(1, "cannot open file '%s'", filename);
-

          +

          @@ -25280,7 +25280,7 @@ jQuery(function ($) { <error><message>Does not compute</message></error> JSON:: "error": { "message": "Does not compute" } -
          +

          @@ -25290,7 +25290,7 @@ jQuery(function ($) {

          libxo automatically initializes the locale based on setting of the environment variables LC_CTYPE, LANG, and LC_ALL. The first of this list of variables is used and if none of the variables, the locale defaults to "UTF‑8". The caller may wish to avoid this behavior, and can do so by calling the xo_no_setlocale() function.

               void xo_no_setlocale (void);
-
          +

          @@ -25318,7 +25318,7 @@ jQuery(function ($) { xo_syslog(LOG_INFO, "poofd-invalid-state", "state {:current/%u} is invalid {:connection/%u}", state, conn); -

          The developer should be aware that the message name may be used in the future to allow access to further information, including documentation. Care should be taken to choose quality, descriptive names.

          +

          The developer should be aware that the message name may be used in the future to allow access to further information, including documentation. Care should be taken to choose quality, descriptive names.

          Section Contents:

          • Section 5.5.1
            • @@ -25336,7 +25336,7 @@ jQuery(function ($) { xo_syslog(LOG_ERR | LOG_AUTH, "login-failed", "Login failed; user '{:user}' from host '{:address}'", user, addr); -

            These values are defined in <syslog.h>.

            +

            These values are defined in <syslog.h>.

            The priority value indicates the importance and potential impact of each message.

        Function
        @@ -25484,7 +25484,7 @@ jQuery(function ($) { ... [poofd-missing-file@32473 filename="/etc/poofd.conf" error="Permission denied"] '/etc/poofd.conf' not found: Permission denied - +

        @@ -25514,7 +25514,7 @@ jQuery(function ($) { xo_vsyslog(LOG_ERR, name, fmt, vap); va_end(vap); } -
        +

        @@ -25525,7 +25525,7 @@ jQuery(function ($) { 
             void
     xo_open_log (const char *ident, int logopt, int facility);
-
        +

        @@ -25536,7 +25536,7 @@ jQuery(function ($) { 
             void
     xo_close_log (void);
-
        +

        @@ -25550,7 +25550,7 @@ jQuery(function ($) { Example: setlogmask(LOG_UPTO(LOG_WARN)); -
        +

        @@ -25562,7 +25562,7 @@ jQuery(function ($) { 
             void
     xo_set_syslog_enterprise_id (unsigned short eid);
-

        Enterprise IDs are administered by IANA, the Internet Assigned Number Authority. The complete list is EIDs on their web site:

        +

        Enterprise IDs are administered by IANA, the Internet Assigned Number Authority. The complete list is EIDs on their web site:

        https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers

        New EIDs can be requested from IANA using the following page:

        http://pen.iana.org/pen/PenApplication.page

        @@ -25605,7 +25605,7 @@ jQuery(function ($) { % ls -1 lib/libxo/extensions/*.enc lib/libxo/extensions/cbor.enc lib/libxo/extensions/test.enc -
        +

        @@ -25615,7 +25615,7 @@ jQuery(function ($) {

        Each encoder must export a symbol used to access the library, which must have the following signature:

             int xo_encoder_library_init (XO_ENCODER_INIT_ARGS);
-

        XO_ENCODER_INIT_ARGS is a macro defined in xo_encoder.h that defines an argument called "arg", a pointer of the type xo_encoder_init_args_t. This structure contains two fields:

        +

        XO_ENCODER_INIT_ARGS is a macro defined in xo_encoder.h that defines an argument called "arg", a pointer of the type xo_encoder_init_args_t. This structure contains two fields:

        • xei_version is the version number of the API as implemented within libxo. This version is currently as 1 using XO_ENCODER_VERSION. This number can be checked to ensure compatibility. The working assumption is that all versions should be backward compatible, but each side may need to accurately know the version supported by the other side. xo_encoder_library_init can optionally check this value, and must then set it to the version number used by the encoder, allowing libxo to detect version differences and react accordingly. For example, if version 2 adds new operations, then libxo will know that an encoding library that set xei_version to 1 cannot be expected to handle those new operations.
          • @@ -25737,7 +25737,7 @@ jQuery(function ($) { <div class="data" data-tag="weight">6</div> <div class="text"> pounds.</div> </div> -

          The "--wrap <path>" option can be used to wrap emitted content in a specific hierarchy. The path is a set of hierarchical names separated by the '/' character.

          +

          The "--wrap <path>" option can be used to wrap emitted content in a specific hierarchy. The path is a set of hierarchical names separated by the '/' character.

               xo --wrap top/a/b/c '{:tag}' value
 
@@ -25761,7 +25761,7 @@ jQuery(function ($) {
         }
       }
     }
-

          The "--open <path>" and "--close <path>" can be used to emit hierarchical information without the matching close and open tag. This allows a shell script to emit open tags, data, and then close tags. The "‑‑depth" option may be used to set the depth for indentation. The "‑‑leading‑xpath" may be used to prepend data to the XPath values used for HTML output style.

          +

          The "--open <path>" and "--close <path>" can be used to emit hierarchical information without the matching close and open tag. This allows a shell script to emit open tags, data, and then close tags. The "‑‑depth" option may be used to set the depth for indentation. The "‑‑leading‑xpath" may be used to prepend data to the XPath values used for HTML output style.

               #!/bin/sh
     xo --open top/data
@@ -25779,7 +25779,7 @@ jQuery(function ($) {
         "tag": "value"
       }
     }
-

          Section Contents:

          +

          Section Contents:

          • Section 6.1
          • Section 6.2
            • @@ -25808,7 +25808,7 @@ jQuery(function ($) { --wrap <path> Wrap output in a set of containers --xml OR -X Generate XML output --xpath Add XPath data to HTML output); -
        +

        @@ -25821,7 +25821,7 @@ jQuery(function ($) { % ./xo/xo -p -X 'The {:product} is {:status}\n' stereo "in route" <product>stereo</product> <status>in route</status> -
        +

        @@ -25877,7 +25877,7 @@ jQuery(function ($) { % xolint.pl -t xolint.c xolint.c: 16: error: anchor format should be "%d" 16 xo_emit("{[:/%s}"); -

        The "‑I" option will generate a table of xo_info_t structures ,

        +

        The "‑I" option will generate a table of xo_info_t structures ,

        The "‑V" option does not report errors, but prints a complete list of all field names, sorted alphabetically. The output can help spot inconsistencies and spelling errors.

        @@ -25951,7 +25951,7 @@ jQuery(function ($) { --keyword=xo_emit_warn -C -E -n --foreign-user \ -o foo.pot.raw foo.c % xopo -f foo.pot.raw -o foo.pot -

        Use of the "‑‑no‑wrap" option for xgettext is required to ensure that incoming msgid strings are not wrapped across multiple lines.

        +

        Use of the "‑‑no‑wrap" option for xgettext is required to ensure that incoming msgid strings are not wrapped across multiple lines.

        @@ -26053,7 +26053,7 @@ jQuery(function ($) { field power; } } -

        These tag definitions are compiled into field definitions that are triggered when matching XML elements are seen. ODL also supports other means of defining output.

        +

        These tag definitions are compiled into field definitions that are triggered when matching XML elements are seen. ODL also supports other means of defining output.

        The roles and modifiers describe these details.

        In moving these ideas to bsd, two things had to happen: the formatting had to happen at the source since BSD won't have a JUNOS-like CLI to do the rendering, and we can't depend on external data models like ODL, which was seen as too hard a sell to the BSD community.

        The results were that the xo_emit strings are used to encode the roles, modifiers, names, and formats. They are dense and a bit cryptic, but not so unlike printf format strings that developers will be lost.

        @@ -26085,7 +26085,7 @@ jQuery(function ($) { /proc-entry[process-id == $pid]/proc-name) { ... } -

        Find someone else who is expressing similar data and follow their fields and hierarchy. Remember the quote is not "Consistency is the hobgoblin of little minds", but "A foolish consistency is the hobgoblin of little minds".

        +

        Find someone else who is expressing similar data and follow their fields and hierarchy. Remember the quote is not "Consistency is the hobgoblin of little minds", but "A foolish consistency is the hobgoblin of little minds".

        Use containment as scoping
        @@ -26142,10 +26142,10 @@ jQuery(function ($) {

        The message "A percent sign appearing in text is a literal" can be caused by code like:

             xo_emit("cost: %d", cost);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{L:cost}: {:cost/%d}", cost);
-

        This can be a bit surprising and could be a field that was not properly converted to a libxo-style format string.

        +

        This can be a bit surprising and could be a field that was not properly converted to a libxo-style format string.

        @@ -26156,10 +26156,10 @@ jQuery(function ($) {

        The message "Unknown long name for role/modifier" can be caused by code like:

             xo_emit("{,humanization:value}", value);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{,humanize:value}", value);
-

        The hn-* modifiers (hn-decimal, hn-space, hn-1000) are only valid for fields with the {h:} modifier.

        +

        The hn-* modifiers (hn-decimal, hn-space, hn-1000) are only valid for fields with the {h:} modifier.

        @@ -26171,10 +26171,10 @@ jQuery(function ($) {

        A common typo:

             xo_emit("{T:Min} T{:Max}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{T:Min} {T:Max}");
-

        Twiddling the "{" and the field role is a common typo.

        +

        Twiddling the "{" and the field role is a common typo.

        @@ -26185,10 +26185,10 @@ jQuery(function ($) {

        The message "Encoding format uses different number of arguments" can be caused by code like:

             xo_emit("{:name/%6.6s %%04d/%s}", name, number);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:name/%6.6s %04d/%s-%d}", name, number);
-

        Both format should consume the same number of arguments off the stack

        +

        Both format should consume the same number of arguments off the stack

        @@ -26199,10 +26199,10 @@ jQuery(function ($) {

        The message "Only one field role can be used" can be caused by code like:

             xo_emit("{LT:Max}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{T:Max}");
-

        +

        @@ -26212,10 +26212,10 @@ jQuery(function ($) {

        The message "Potential missing slash after C, D, N, L, or T with format" can be caused by code like:

             xo_emit("{T:%6.6s}\n", "Max");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{T:/%6.6s}\n", "Max");
-

        The "%6.6s" will be a literal, not a field format. While it's possibly valid, it's likely a missing "/".

        +

        The "%6.6s" will be a literal, not a field format. While it's possibly valid, it's likely a missing "/".

        @@ -26226,7 +26226,7 @@ jQuery(function ($) {

        The message "An encoding format cannot be given (roles: DNLT)" can be caused by code like:

             xo_emit("{T:Max//%s}", "Max");
-

        Fields with the C, D, N, L, and T roles are not emitted in the 'encoding' style (JSON, XML), so an encoding format would make no sense.

        +

        Fields with the C, D, N, L, and T roles are not emitted in the 'encoding' style (JSON, XML), so an encoding format would make no sense.

        @@ -26237,7 +26237,7 @@ jQuery(function ($) {

        The message "Format cannot be given when content is present (roles: CDLN)" can be caused by code like:

             xo_emit("{N:Max/%6.6s}", "Max");
-

        Fields with the C, D, L, or N roles can't have both static literal content ("{L:Label}") and a format ("{L:/%s}"). This error will also occur when the content has a backslash in it, like "{N:Type of I/O}"; backslashes should be escaped, like "{N:Type of I\\/O}". Note the double backslash, one for handling 'C' strings, and one for libxo.

        +

        Fields with the C, D, L, or N roles can't have both static literal content ("{L:Label}") and a format ("{L:/%s}"). This error will also occur when the content has a backslash in it, like "{N:Type of I/O}"; backslashes should be escaped, like "{N:Type of I\\/O}". Note the double backslash, one for handling 'C' strings, and one for libxo.

        @@ -26248,10 +26248,10 @@ jQuery(function ($) {

        The message "Field has color without fg- or bg- (role: C)" can be caused by code like:

             xo_emit("{C:green}{:foo}{C:}", x);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{C:fg-green}{:foo}{C:}", x);
-

        Colors must be prefixed by either "fg‑" or "bg‑".

        +

        Colors must be prefixed by either "fg‑" or "bg‑".

        @@ -26262,10 +26262,10 @@ jQuery(function ($) {

        The message "Field has invalid color or effect (role: C)" can be caused by code like:

             xo_emit("{C:fg-purple,bold}{:foo}{C:gween}", x);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{C:fg-red,bold}{:foo}{C:fg-green}", x);
-

        The list of colors and effects are limited. The set of colors includes default, black, red, green, yellow, blue, magenta, cyan, and white, which must be prefixed by either "fg‑" or "bg‑". Effects are limited to bold, no-bold, underline, no-underline, inverse, no-inverse, normal, and reset. Values must be separated by commas.

        +

        The list of colors and effects are limited. The set of colors includes default, black, red, green, yellow, blue, magenta, cyan, and white, which must be prefixed by either "fg‑" or "bg‑". Effects are limited to bold, no-bold, underline, no-underline, inverse, no-inverse, normal, and reset. Values must be separated by commas.

        @@ -26276,10 +26276,10 @@ jQuery(function ($) {

        The message "Field has humanize modifier but no format string" can be caused by code like:

             xo_emit("{h:value}", value);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{h:value/%d}", value);
-

        Humanization is only value for numbers, which are not likely to use the default format ("%s").

        +

        Humanization is only value for numbers, which are not likely to use the default format ("%s").

        @@ -26290,10 +26290,10 @@ jQuery(function ($) {

        The message "Field has hn-* modifier but not 'h' modifier" can be caused by code like:

             xo_emit("{,hn-1000:value}", value);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{h,hn-1000:value}", value);
-

        The hn-* modifiers (hn-decimal, hn-space, hn-1000) are only valid for fields with the {h:} modifier.

        +

        The hn-* modifiers (hn-decimal, hn-space, hn-1000) are only valid for fields with the {h:} modifier.

        @@ -26304,10 +26304,10 @@ jQuery(function ($) {

        The message "Value field must have a name (as content)")" can be caused by code like:

             xo_emit("{:/%s}", "value");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:tag-name/%s}", "value");
-

        The field name is used for XML and JSON encodings. These tags names are static and must appear directly in the field descriptor.

        +

        The field name is used for XML and JSON encodings. These tags names are static and must appear directly in the field descriptor.

        @@ -26318,10 +26318,10 @@ jQuery(function ($) {

        The message "Use hyphens, not underscores, for value field name" can be caused by code like:

             xo_emit("{:no_under_scores}", "bad");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:no-under-scores}", "bad");
-

        Use of hyphens is traditional in XML, and the XOF_UNDERSCORES flag can be used to generate underscores in JSON, if desired. But the raw field name should use hyphens.

        +

        Use of hyphens is traditional in XML, and the XOF_UNDERSCORES flag can be used to generate underscores in JSON, if desired. But the raw field name should use hyphens.

        @@ -26332,10 +26332,10 @@ jQuery(function ($) {

        The message "Value field name cannot start with digit" can be caused by code like:

             xo_emit("{:10-gig/}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:ten-gig/}");
-

        XML element names cannot start with a digit.

        +

        XML element names cannot start with a digit.

        @@ -26346,10 +26346,10 @@ jQuery(function ($) {

        The message "Value field name should be lower case" can be caused by code like:

             xo_emit("{:WHY-ARE-YOU-SHOUTING}", "NO REASON");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:why-are-you-shouting}", "no reason");
-

        Lower case is more civilized. Even TLAs should be lower case to avoid scenarios where the differences between "XPath" and "Xpath" drive your users crazy. Lower case rules the seas.

        +

        Lower case is more civilized. Even TLAs should be lower case to avoid scenarios where the differences between "XPath" and "Xpath" drive your users crazy. Lower case rules the seas.

        @@ -26360,10 +26360,10 @@ jQuery(function ($) {

        The message "Value field name should be longer than two characters" can be caused by code like:

             xo_emit("{:x}", "mumble");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:something-meaningful}", "mumble");
-

        Field names should be descriptive, and it's hard to be descriptive in less than two characters. Consider your users and try to make something more useful. Note that this error often occurs when the field type is placed after the colon ("{:T/%20s}"), instead of before it ("{T:/20s}").

        +

        Field names should be descriptive, and it's hard to be descriptive in less than two characters. Consider your users and try to make something more useful. Note that this error often occurs when the field type is placed after the colon ("{:T/%20s}"), instead of before it ("{T:/20s}").

        @@ -26374,10 +26374,10 @@ jQuery(function ($) {

        The message "Value field name contains invalid character" can be caused by code like:

             xo_emit("{:cost-in-$$/%u}", 15);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:cost-in-dollars/%u}", 15);
-

        An invalid character is often a sign of a typo, like "{:]}" instead of "{]:}". Field names are restricted to lower-case characters, digits, and hyphens.

        +

        An invalid character is often a sign of a typo, like "{:]}" instead of "{]:}". Field names are restricted to lower-case characters, digits, and hyphens.

        @@ -26388,10 +26388,10 @@ jQuery(function ($) {

        The message "decoration field contains invalid character" can be caused by code like:

             xo_emit("{D:not good}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{D:((}{:good}{D:))}", "yes");
-

        This is minor, but fields should use proper roles. Decoration fields are meant to hold punctuation and other characters used to decorate the content, typically to make it more readable to human readers.

        +

        This is minor, but fields should use proper roles. Decoration fields are meant to hold punctuation and other characters used to decorate the content, typically to make it more readable to human readers.

        @@ -26402,10 +26402,10 @@ jQuery(function ($) {

        The message "Anchor content should be decimal width" can be caused by code like:

             xo_emit("{[:mumble}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{[:32}");
-

        Anchors need an integer value to specify the width of the set of anchored fields. The value can be positive (for left padding/right justification) or negative (for right padding/left justification) and can appear in either the start or stop anchor field descriptor.

        +

        Anchors need an integer value to specify the width of the set of anchored fields. The value can be positive (for left padding/right justification) or negative (for right padding/left justification) and can appear in either the start or stop anchor field descriptor.

        @@ -26416,10 +26416,10 @@ jQuery(function ($) {

        The message "Anchor format should be "%d"" can be caused by code like:

             xo_emit("{[:/%s}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{[:/%d}");
-

        Anchors only grok integer values, and if the value is not static, if must be in an 'int' argument, represented by the "%d" format. Anything else is an error.

        +

        Anchors only grok integer values, and if the value is not static, if must be in an 'int' argument, represented by the "%d" format. Anything else is an error.

        @@ -26430,10 +26430,10 @@ jQuery(function ($) {

        The message "Anchor cannot have both format and encoding format")" can be caused by code like:

             xo_emit("{[:32/%d}");
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{[:32}");
-

        Anchors can have a static value or argument for the width, but cannot have both.

        +

        Anchors can have a static value or argument for the width, but cannot have both.

        @@ -26444,10 +26444,10 @@ jQuery(function ($) {

        The message "Max width only valid for strings" can be caused by code like:

             xo_emit("{:tag/%2.4.6d}", 55);
-

        This code should be replaced with code like:

        +

        This code should be replaced with code like:

             xo_emit("{:tag/%2.6d}", 55);
-

        libxo allows a true 'max width' in addition to the traditional printf-style 'max number of bytes to use for input'. But this is supported only for string values, since it makes no sense for non-strings. This error may occur from a typo, like "{:tag/%6..6d}" where only one period should be used.

        +

        libxo allows a true 'max width' in addition to the traditional printf-style 'max number of bytes to use for input'. But this is supported only for string values, since it makes no sense for non-strings. This error may occur from a typo, like "{:tag/%6..6d}" where only one period should be used.

        @@ -26492,7 +26492,7 @@ jQuery(function ($) { make make test sudo make install -

        libxo uses a distinct "build" directory to keep generated files separated from source files.

        +

        libxo uses a distinct "build" directory to keep generated files separated from source files.

        Use "../configure --help" to display available configuration options, which include the following:

           --enable-warnings      Turn on compiler warnings
@@ -26502,7 +26502,7 @@ jQuery(function ($) {
   --disable-libxo-options  Turn off support for LIBXO_OPTIONS
   --with-gettext=PFX     Specify location of gettext installation
   --with-libslax-prefix=PFX  Specify location of libslax config
-

        Compiler warnings are a very good thing, but recent compiler version have added some very pedantic checks. While every attempt is made to keep libxo code warning-free, warnings are now optional. If you are doing development work on libxo, it is required that you use --enable-warnings to keep the code warning free, but most users need not use this option.

        +

        Compiler warnings are a very good thing, but recent compiler version have added some very pedantic checks. While every attempt is made to keep libxo code warning-free, warnings are now optional. If you are doing development work on libxo, it is required that you use --enable-warnings to keep the code warning free, but most users need not use this option.

        libxo provides the --enable-text-only option to reduce the footprint of the library for smaller installations. XML, JSON, and HTML rendering logic is removed.

        The gettext library does not provide a simple means of learning its location, but libxo will look for it in /usr and /opt/local. If installed elsewhere, the installer will need to provide this information using the --with-gettext=/dir/path option.

        libslax is not required by libxo; it contains the "oxtradoc" program used to format documentation.

        @@ -26516,7 +26516,7 @@ jQuery(function ($) { 
             How do I convert an existing command line application?
-

        There are three basic steps for converting command line application to use libxo.

        +

        There are three basic steps for converting command line application to use libxo.

        • Setting up the context
          • @@ -26540,7 +26540,7 @@ jQuery(function ($) {

          To use libxo, you'll need to include the "xo.h" header file in your source code files:

               #include <libxo/xo.h>
-

          In your main() function, you'll need to call xo_parse_args to handling argument parsing (Section 5.4.1). This function removes libxo-specific arguments the program's argv and returns either the number of remaining arguments or -1 to indicate an error.

          +

          In your main() function, you'll need to call xo_parse_args to handling argument parsing (Section 5.4.1). This function removes libxo-specific arguments the program's argv and returns either the number of remaining arguments or -1 to indicate an error.

               int main (int argc, char **argv)
     {
@@ -26549,10 +26549,10 @@ jQuery(function ($) {
             return argc;
         ....
     }
-

          At the bottom of your main(), you'll need to call xo_finish() to complete output processing for the default handle (Section 5.1). libxo provides the xo_finish_atexit function that is suitable for use with the atexit(3) function.

          +

          At the bottom of your main(), you'll need to call xo_finish() to complete output processing for the default handle (Section 5.1). libxo provides the xo_finish_atexit function that is suitable for use with the atexit(3) function.

               atexit(xo_finish_atexit);
-
          +

          @@ -26563,23 +26563,23 @@ jQuery(function ($) { 
               printf("There are %d %s events\n", count, etype);
     xo_emit("There are {:count/%d} {:event} events\n", count, etype);
-

          "count" and "event" are used as names for JSON and XML output. The "count" field uses the format "%d" and "event" uses the default "%s" format. Both are "value" roles, which is the default role.

          +

          "count" and "event" are used as names for JSON and XML output. The "count" field uses the format "%d" and "event" uses the default "%s" format. Both are "value" roles, which is the default role.

          Since text outside of output fields is passed verbatim, other roles are less important, but their proper use can help make output more useful. The "note" and "label" roles allow HTML output to recognize the relationship between text and the associated values, allowing appropriate "hover" and "onclick" behavior. Using the "units" role allows the presentation layer to perform conversions when needed. The "warning" and "error" roles allows use of color and font to draw attention to warnings. The "padding" role makes the use of vital whitespace more clear (Section 3.2.1.6).

          The "title" role indicates the headings of table and sections. This allows HTML output to use CSS to make this relationship more obvious.

               printf("Statistics:\n");
     xo_emit("{T:Statistics}:\n");
-

          The "color" roles controls foreground and background colors, as well as effects like bold and underline (see Section 3.2.1.1).

          +

          The "color" roles controls foreground and background colors, as well as effects like bold and underline (see Section 3.2.1.1).

               xo_emit("{C:bold}required{C:}\n");
-

          Finally, the start- and stop-anchor roles allow justification and padding over multiple fields (see Section 3.2.1.10).

          +

          Finally, the start- and stop-anchor roles allow justification and padding over multiple fields (see Section 3.2.1.10).

               snprintf(buf, sizeof(buf), "(%u/%u/%u)", min, ave, max);
     printf("%30s", buf);
 
     xo_emit("{[:30}({:minimum/%u}/{:average/%u}/{:maximum/%u}{]:}",
             min, ave, max);
-
          +

          @@ -26602,7 +26602,7 @@ jQuery(function ($) { xo_close_instance("table"); } xo_close_list("table"); -

          The open and close list functions are used before and after the list, and the open and close instance functions are used before and after each instance with in the list.

          +

          The open and close list functions are used before and after the list, and the open and close instance functions are used before and after each instance with in the list.

          Typically these developer looks for a "for" loop as an indication of where to put these calls.

          In addition, the open and close container functions allow for organization levels of hierarchy.

          @@ -26616,7 +26616,7 @@ jQuery(function ($) {
     xo_emit("{P:    }{L:Active:    }{:active/%lu}\n", active);
     xo_emit("{P:    }{L:Inactive:  }{:inactive/%lu}\n", inactive);
     xo_close_container("paging-information");
-
          +

          @@ -26629,7 +26629,7 @@ jQuery(function ($) { xo_err(1, "cannot open output file: %s", file); xo_emit_err(1, "cannot open output file: {:filename}", file); -
          +

          @@ -26644,7 +26644,7 @@ jQuery(function ($) { 

               How do I use libxo to support internationalization?
-

          libxo allows format and field strings to be used a keys into message catalogs to enable translation into a user's native language by invoking the standard gettext(3) functions.

          +

          libxo allows format and field strings to be used a keys into message catalogs to enable translation into a user's native language by invoking the standard gettext(3) functions.

          gettext setup is a bit complicated: text strings are extracted from source files into "portable object template" (.pot) files using the "xgettext" command. For each language, this template file is used as the source for a message catalog in the "portable object" (.po) format, which are translated by hand and compiled into "machine object" (.mo) files using the "msgfmt" command. The .mo files are then typically installed in the /usr/share/locale or /opt/local/share/locale directories. At run time, the user's language settings are used to select a .mo file which is searched for matching messages. Text strings in the source code are used as keys to look up the native language strings in the .mo file.

          Since the xo_emit format string is used as the key into the message catalog, libxo removes unimportant field formatting and modifiers from the format string before use so that minor formatting changes will not impact the expensive translation process. We don't want a developer change such as changing "/%06d" to "/%08d" to force hand inspection of all .po files. The simplified version can be generated for a single message using the "xopo -s <text>" command, or an entire .pot can be translated using the "xopo -f <input> -o <output>" command.

          @@ -26679,10 +26679,10 @@ jQuery(function ($) {
         # Install the .mo file
         sudo cp po/my_lang/LC_MESSAGES/foo.mo \
                 /opt/local/share/locale/my_lang/LC_MESSAGE/
-

          Once these steps are complete, you can use the "gettext" command to test the message catalog:

          +

          Once these steps are complete, you can use the "gettext" command to test the message catalog:

               gettext -d foo -e "some text"
-

          Section Contents:

          +

          Section Contents:

          @@ -26705,14 +26705,14 @@ jQuery(function ($) { xo_emit("{G:}Received {:received/%zu} {Ngp:byte,bytes} " "from {g:server} server\n", counter, "web"); -

          libxo will see the "{G:}" role and will first simplify the format string, removing field formats and modifiers.

          +

          libxo will see the "{G:}" role and will first simplify the format string, removing field formats and modifiers.

               "Received {:received} {N:byte,bytes} from {:server} server\n"
-

          libxo calls gettext(3) with that string to get a localized version. If your language were Pig Latin, the result might look like:

          +

          libxo calls gettext(3) with that string to get a localized version. If your language were Pig Latin, the result might look like:

               "Eceivedray {:received} {N:byte,bytes} omfray "
                "{:server} erversay\n"
-

          Note the field names do not change and they should not be translated. The contents of the note ("byte,bytes") should also not be translated, since the "g" modifier will need the untranslated value as the key for the message catalog.

          +

          Note the field names do not change and they should not be translated. The contents of the note ("byte,bytes") should also not be translated, since the "g" modifier will need the untranslated value as the key for the message catalog.

          The field "{g:server}" requests the rendered value of the field be translated using gettext(3). In this example, "web" would be used.

          The field "{Ngp:byte,bytes}" shows an example of plural form using the "p" modifier with the "g" modifier. The base singular and plural forms appear inside the field, separated by a comma. At run time, libxo uses the previous field's numeric value to decide which form to use by calling ngettext(3).

          If a domain name is needed, it can be supplied as the content of the {G:} role. Domain names remain in use throughout the format string until cleared with another domain name.

          @@ -26722,7 +26722,7 @@ jQuery(function ($) { xo_emit("{G:dns}Host {:hostname} not found: " "%d({G:strerror}{g:%m})\n", name, errno); -

          +
          @@ -26833,7 +26833,7 @@ jQuery(function ($) { return 0; } -

          Text output:

          +

          Text output:

               % ./testxo --libxo text
     Item 'gum':
@@ -26866,7 +26866,7 @@ jQuery(function ($) {
        In stock: 45
        On order: 1
        SKU: GRO-000-533
-

          JSON output:

          +

          JSON output:

               % ./testxo --libxo json,pretty
     "top": {
@@ -26921,7 +26921,7 @@ jQuery(function ($) {
         ]
       }
     }
-

          XML output:

          +

          XML output:

               % ./testxo --libxo pretty,xml
     <top>
@@ -26972,7 +26972,7 @@ jQuery(function ($) {
         </item>
       </data>
     </top>
-

          HMTL output:

          +

          HMTL output:

               % ./testxo --libxo pretty,html
     <div class="line">
@@ -27167,7 +27167,7 @@ jQuery(function ($) {
       <div class="text">: </div>
       <div class="data" data-tag="sku">GRO-000-533</div>
     </div>
-

          HTML output with xpath and info flags:

          +

          HTML output with xpath and info flags:

               % ./testxo --libxo pretty,html,xpath,info
     <div class="line">
@@ -27422,7 +27422,7 @@ jQuery(function ($) {
            data-xpath="/top/data/item/sku" data-type="string"
            data-help="Stock Keeping Unit">GRO-000-533</div>
     </div>
-
          +
          diff --git a/doc/options.rst b/doc/options.rst new file mode 100644 index 000000000000..9219037dcd37 --- /dev/null +++ b/doc/options.rst @@ -0,0 +1,164 @@ + +.. index:: --libxo +.. index:: Options + +.. _options: + +Command-line Arguments +====================== + +libxo uses command line options to trigger rendering behavior. There +are multiple conventions for passing options, all using the +"`--libxo`" option:: + + --libxo + --libxo= + --libxo: + +The *brief-options* is a series of single letter abbrevations, where +the *options* is a comma-separated list of words. Both provide access +to identical functionality. The following invocations are all +identical in outcome:: + + my-app --libxo warn,pretty arg1 + my-app --libxo=warn,pretty arg1 + my-app --libxo:WP arg1 + +Programs using libxo are expecting to call the xo_parse_args function +to parse these arguments. See :ref:`xo_parse_args` for details. + +Option Keywords +--------------- + +Options is a comma-separated list of tokens that correspond to output +styles, flags, or features: + +=============== ======================================================= +Token Action +=============== ======================================================= +color Enable colors/effects for display styles (TEXT, HTML) +colors=xxxx Adjust color output values +dtrt Enable "Do The Right Thing" mode +flush Flush after every libxo function call +flush-line Flush after every line (line-buffered) +html Emit HTML output +indent=xx Set the indentation level +info Add info attributes (HTML) +json Emit JSON output +keys Emit the key attribute for keys (XML) +log-gettext Log (via stderr) each gettext(3) string lookup +log-syslog Log (via stderr) each syslog message (via xo_syslog) +no-humanize Ignore the {h:} modifier (TEXT, HTML) +no-locale Do not initialize the locale setting +no-retain Prevent retaining formatting information +no-top Do not emit a top set of braces (JSON) +not-first Pretend the 1st output item was not 1st (JSON) +pretty Emit pretty-printed output +retain Force retaining formatting information +text Emit TEXT output +underscores Replace XML-friendly "-"s with JSON friendly "_"s +units Add the 'units' (XML) or 'data-units (HTML) attribute +warn Emit warnings when libxo detects bad calls +warn-xml Emit warnings in XML +xml Emit XML output +xpath Add XPath expressions (HTML) +=============== ======================================================= + +Most of these option are simple and direct, but some require +additional details: + +- "colors" is described in :ref:`color-mapping`. +- "flush-line" performs line buffering, even when the output is not + directed to a TTY device. +- "info" generates additional data for HTML, encoded in attributes + using names that state with "data-". +- "keys" adds a "key" attribute for XML output to indicate that a leaf + is an identifier for the list member. +- "no-humanize" avoids "humanizing" numeric output (see + :ref:`humanize-modifier` for details). +- "no-locale" instructs libxo to avoid translating output to the + current locale. +- "no-retain" disables the ability of libxo to internally retain + "compiled" information about formatting strings (see :ref:`retain` + for details). +- "underscores" can be used with JSON output to change XML-friendly + names with dashes into JSON-friendly name with underscores. +- "warn" allows libxo to emit warnings on stderr when application code + make incorrect calls. +- "warn-xml" causes those warnings to be placed in XML inside the + output. + +Brief Options +------------- + +The brief options are simple single-letter aliases to the normal +keywords, as detailed below: + +======== ============================================= + Option Action +======== ============================================= + c Enable color/effects for TEXT/HTML + F Force line-buffered flushing + H Enable HTML output (XO_STYLE_HTML) + I Enable info output (XOF_INFO) + i Indent by + J Enable JSON output (XO_STYLE_JSON) + k Add keys to XPATH expressions in HTML + n Disable humanization (TEXT, HTML) + P Enable pretty-printed output (XOF_PRETTY) + T Enable text output (XO_STYLE_TEXT) + U Add units to HTML output + u Change "-"s to "_"s in element names (JSON) + W Enable warnings (XOF_WARN) + X Enable XML output (XO_STYLE_XML) + x Enable XPath data (XOF_XPATH) +======== ============================================= + +.. index:: Colors + +.. _color-mapping: + +Color Mapping +------------- + +The "colors" option takes a value that is a set of mappings from the +pre-defined set of colors to new foreground and background colors. +The value is a series of "fg/bg" values, separated by a "+". Each +pair of "fg/bg" values gives the colors to which a basic color is +mapped when used as a foreground or background color. The order is +the mappings is: + +- black +- red +- green +- yellow +- blue +- magenta +- cyan +- white + +Pairs may be skipped, leaving them mapped as normal, as are missing +pairs or single colors. + +For example consider the following xo_emit call:: + + xo_emit("{C:fg-red,bg-green}Merry XMas!!{C:}\n"); + +To turn all colored output to red-on-blue, use eight pairs of +"red/blue" mappings separated by "+"s:: + + --libxo colors=red/blue+red/blue+red/blue+red/blue+\ + red/blue+red/blue+red/blue+red/blue + +To turn the red-on-green text to magenta-on-cyan, give a "magenta" +foreground value for red (the second mapping) and a "cyan" background +to green (the third mapping):: + + --libxo colors=+magenta+/cyan + +Consider the common situation where blue output looks unreadable on a +terminal session with a black background. To turn both "blue" +foreground and background output to "yellow", give only the fifth +mapping, skipping the first four mappings with bare "+"s:: + + --libxo colors=++++yellow/yellow diff --git a/doc/xo.rst b/doc/xo.rst new file mode 100644 index 000000000000..9475c103b1ba --- /dev/null +++ b/doc/xo.rst @@ -0,0 +1,125 @@ + +.. index:: --libxo, xo + +The "xo" Utility +================ + +The `xo` utility allows command line access to the functionality of +the libxo library. Using `xo`, shell scripts can emit XML, JSON, and +HTML using the same commands that emit text output. + +The style of output can be selected using a specific option: "-X" for +XML, "-J" for JSON, "-H" for HTML, or "-T" for TEXT, which is the +default. The "--style