freebsd-nq/gnu/usr.bin/ptx/ptx.info
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This is Info file ptx.info, produced by Makeinfo-1.47 from the input
file ./ptx.texinfo.
This file documents the `ptx' command, which has the purpose of
generated permuted indices for group of files.
Copyright (C) 1990, 1991, 1993 by the Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Foundation.

File: ptx.info, Node: Top, Next: Invoking ptx, Prev: (dir), Up: (dir)
Introduction
************
This is the 0.3 beta release of `ptx', the GNU version of a permuted
index generator. This software has the main goal of providing a
replacement for the traditional `ptx' as found on System V machines,
able to handle small files quickly, while providing a platform for more
development.
This version reimplements and extends traditional `ptx'. Among
other things, it can produce a readable "KWIC" (keywords in their
context) without the need of `nroff', there is also an option to
produce TeX compatible output. This version does not handle huge input
files, that is, those files which do not fit in memory all at once.
*Please note* that an overall renaming of all options is
foreseeable. In fact, GNU ptx specifications are not frozen yet.
* Menu:
* Invoking ptx:: How to use this program
* Compatibility:: The GNU extensions to `ptx'
-- The Detailed Node Listing --
How to use this program
* General options:: Options which affect general program behaviour.
* Charset selection:: Underlying character set considerations.
* Input processing:: Input fields, contexts, and keyword selection.
* Output formatting:: Types of output format, and sizing the fields.

File: ptx.info, Node: Invoking ptx, Next: Compatibility, Prev: Top, Up: Top
How to use this program
***********************
This tool reads a text file and essentially produces a permuted
index, with each keyword in its context. The calling sketch is one of:
ptx [OPTION ...] [FILE ...]
or:
ptx -G [OPTION ...] [INPUT [OUTPUT]]
The `-G' (or its equivalent: `--traditional') option disables all
GNU extensions and revert to traditional mode, thus introducing some
limitations, and changes several of the program's default option values.
When `-G' is not specified, GNU extensions are always enabled. GNU
extensions to `ptx' are documented wherever appropriate in this
document. See *Note Compatibility:: for an explicit list of them.
Individual options are explained later in this document.
When GNU extensions are enabled, there may be zero, one or several
FILE after the options. If there is no FILE, the program reads the
standard input. If there is one or several FILE, they give the name of
input files which are all read in turn, as if all the input files were
concatenated. However, there is a full contextual break between each
file and, when automatic referencing is requested, file names and line
numbers refer to individual text input files. In all cases, the
program produces the permuted index onto the standard output.
When GNU extensions are *not* enabled, that is, when the program
operates in traditional mode, there may be zero, one or two parameters
besides the options. If there is no parameters, the program reads the
standard input and produces the permuted index onto the standard output.
If there is only one parameter, it names the text INPUT to be read
instead of the standard input. If two parameters are given, they give
respectively the name of the INPUT file to read and the name of the
OUTPUT file to produce. *Be very careful* to note that, in this case,
the contents of file given by the second parameter is destroyed. This
behaviour is dictated only by System V `ptx' compatibility, because GNU
Standards discourage output parameters not introduced by an option.
Note that for *any* file named as the value of an option or as an
input text file, a single dash `-' may be used, in which case standard
input is assumed. However, it would not make sense to use this
convention more than once per program invocation.
* Menu:
* General options:: Options which affect general program behaviour.
* Charset selection:: Underlying character set considerations.
* Input processing:: Input fields, contexts, and keyword selection.
* Output formatting:: Types of output format, and sizing the fields.

File: ptx.info, Node: General options, Next: Charset selection, Prev: Invoking ptx, Up: Invoking ptx
General options
===============
`-C'
`--copyright'
Prints a short note about the Copyright and copying conditions,
then exit without further processing.
`-G'
`--traditional'
As already explained, this option disables all GNU extensions to
`ptx' and switch to traditional mode.
`--help'
Prints a short help on standard output, then exit without further
processing.
`--version'
Prints the program verison on standard output, then exit without
further processing.

File: ptx.info, Node: Charset selection, Next: Input processing, Prev: General options, Up: Invoking ptx
Charset selection
=================
As it is setup now, the program assumes that the input file is coded
using 8-bit ISO 8859-1 code, also known as Latin-1 character set,
*unless* if it is compiled for MS-DOS, in which case it uses the
character set of the IBM-PC. (GNU `ptx' is not known to work on
smaller MS-DOS machines anymore.) Compared to 7-bit ASCII, the set of
characters which are letters is then different, this fact alters the
behaviour of regular expression matching. Thus, the default regular
expression for a keyword allows foreign or diacriticized letters.
Keyword sorting, however, is still crude; it obeys the underlying
character set ordering quite blindly.
`-f'
`--ignore-case'
Fold lower case letters to upper case for sorting.

File: ptx.info, Node: Input processing, Next: Output formatting, Prev: Charset selection, Up: Invoking ptx
Word selection
==============
`-b FILE'
`--break-file=FILE'
This option is an alternative way to option `-W' for describing
which characters make up words. This option introduces the name
of a file which contains a list of characters which can*not* be
part of one word, this file is called the "Break file". Any
character which is not part of the Break file is a word
constituent. If both options `-b' and `-W' are specified, then
`-W' has precedence and `-b' is ignored.
When GNU extensions are enabled, the only way to avoid newline as a
break character is to write all the break characters in the file
with no newline at all, not even at the end of the file. When GNU
extensions are disabled, spaces, tabs and newlines are always
considered as break characters even if not included in the Break
file.
`-i FILE'
`--ignore-file=FILE'
The file associated with this option contains a list of words
which will never be taken as keywords in concordance output. It
is called the "Ignore file". The file contains exactly one word
in each line; the end of line separation of words is not subject
to the value of the `-S' option.
There is a default Ignore file used by `ptx' when this option is
not specified, usually found in `/usr/local/lib/eign' if this has
not been changed at installation time. If you want to deactivate
the default Ignore file, specify `/dev/null' instead.
`-o FILE'
`--only-file=FILE'
The file associated with this option contains a list of words
which will be retained in concordance output, any word not
mentioned in this file is ignored. The file is called the "Only
file". The file contains exactly one word in each line; the end
of line separation of words is not subject to the value of the
`-S' option.
There is no default for the Only file. In the case there are both
an Only file and an Ignore file, a word will be subject to be a
keyword only if it is given in the Only file and not given in the
Ignore file.
`-r'
`--references'
On each input line, the leading sequence of non white characters
will be taken to be a reference that has the purpose of
identifying this input line on the produced permuted index. See
*Note Output formatting:: for more information about reference
production. Using this option change the default value for option
`-S'.
Using this option, the program does not try very hard to remove
references from contexts in output, but it succeeds in doing so
*when* the context ends exactly at the newline. If option `-r' is
used with `-S' default value, or when GNU extensions are disabled,
this condition is always met and references are completely
excluded from the output contexts.
`-S REGEXP'
`--sentence-regexp=REGEXP'
This option selects which regular expression will describe the end
of a line or the end of a sentence. In fact, there is other
distinction between end of lines or end of sentences than the
effect of this regular expression, and input line boundaries have
no special significance outside this option. By default, when GNU
extensions are enabled and if `-r' option is not used, end of
sentences are used. In this case, the precise REGEX is imported
from GNU emacs:
[.?!][]\"')}]*\\($\\|\t\\| \\)[ \t\n]*
Whenever GNU extensions are disabled or if `-r' option is used, end
of lines are used; in this case, the default REGEXP is just:
\n
Using an empty REGEXP is equivalent to completely disabling end of
line or end of sentence recognition. In this case, the whole file
is considered to be a single big line or sentence. The user might
want to disallow all truncation flag generation as well, through
option `-F ""'. *Note Syntax of Regular Expressions:
(emacs)Regexps.
When the keywords happen to be near the beginning of the input
line or sentence, this often creates an unused area at the
beginning of the output context line; when the keywords happen to
be near the end of the input line or sentence, this often creates
an unused area at the end of the output context line. The program
tries to fill those unused areas by wrapping around context in
them; the tail of the input line or sentence is used to fill the
unused area on the left of the output line; the head of the input
line or sentence is used to fill the unused area on the right of
the output line.
As a matter of convenience to the user, many usual backslashed
escape sequences, as found in the C language, are recognized and
converted to the corresponding characters by `ptx' itself.
`-W REGEXP'
`--word-regexp=REGEXP'
This option selects which regular expression will describe each
keyword. By default, if GNU extensions are enabled, a word is a
sequence of letters; the REGEXP used is `\w+'. When GNU
extensions are disabled, a word is by default anything which ends
with a space, a tab or a newline; the REGEXP used is `[^ \t\n]+'.
An empty REGEXP is equivalent to not using this option, letting the
default dive in. *Note Syntax of Regular Expressions:
(emacs)Regexps.
As a matter of convenience to the user, many usual backslashed
escape sequences, as found in the C language, are recognized and
converted to the corresponding characters by `ptx' itself.

File: ptx.info, Node: Output formatting, Prev: Input processing, Up: Invoking ptx
Output formatting
=================
Output format is mainly controlled by `-O' and `-T' options,
described in the table below. When neither `-O' nor `-T' is selected,
and if GNU extensions are enabled, the program choose an output format
suited for a dumb terminal. Each keyword occurrence is output to the
center of one line, surrounded by its left and right contexts. Each
field is properly justified, so the concordance output could readily be
observed. As a special feature, if automatic references are selected
by option `-A' and are output before the left context, that is, if
option `-R' is *not* selected, then a colon is added after the
reference; this nicely interfaces with GNU Emacs `next-error'
processing. In this default output format, each white space character,
like newline and tab, is merely changed to exactly one space, with no
special attempt to compress consecutive spaces. This might change in
the future. Except for those white space characters, every other
character of the underlying set of 256 characters is transmitted
verbatim.
Output format is further controlled by the following options.
`-g NUMBER'
`--gap-size=NUMBER'
Select the size of the minimum white gap between the fields on the
output line.
`-w NUMBER'
`--width=NUMBER'
Select the output maximum width of each final line. If references
are used, they are included or excluded from the output maximum
width depending on the value of option `-R'. If this option is not
selected, that is, when references are output before the left
context, the output maximum width takes into account the maximum
length of all references. If this options is selected, that is,
when references are output after the right context, the output
maximum width does not take into account the space taken by
references, nor the gap that precedes them.
`-A'
`--auto-reference'
Select automatic references. Each input line will have an
automatic reference made up of the file name and the line ordinal,
with a single colon between them. However, the file name will be
empty when standard input is being read. If both `-A' and `-r'
are selected, then the input reference is still read and skipped,
but the automatic reference is used at output time, overriding the
input reference.
`-R'
`--right-side-refs'
In default output format, when option `-R' is not used, any
reference produced by the effect of options `-r' or `-A' are given
to the far right of output lines, after the right context. In
default output format, when option `-R' is specified, references
are rather given to the beginning of each output line, before the
left context. For any other output format, option `-R' is almost
ignored, except for the fact that the width of references is *not*
taken into account in total output width given by `-w' whenever
`-R' is selected.
This option is automatically selected whenever GNU extensions are
disabled.
`-F STRING'
`--flac-truncation=STRING'
This option will request that any truncation in the output be
reported using the string STRING. Most output fields
theoretically extend towards the beginning or the end of the
current line, or current sentence, as selected with option `-S'.
But there is a maximum allowed output line width, changeable
through option `-w', which is further divided into space for
various output fields. When a field has to be truncated because
cannot extend until the beginning or the end of the current line
to fit in the, then a truncation occurs. By default, the string
used is a single slash, as in `-F /'.
STRING may have more than one character, as in `-F ...'. Also, in
the particular case STRING is empty (`-F ""'), truncation flagging
is disabled, and no truncation marks are appended in this case.
As a matter of convenience to the user, many usual backslashed
escape sequences, as found in the C language, are recognized and
converted to the corresponding characters by `ptx' itself.
`-M STRING'
`--macro-name=STRING'
Select another STRING to be used instead of `xx', while generating
output suitable for `nroff', `troff' or TeX.
`-O'
`--format=roff'
Choose an output format suitable for `nroff' or `troff'
processing. Each output line will look like:
.xx "TAIL" "BEFORE" "KEYWORD_AND_AFTER" "HEAD" "REF"
so it will be possible to write an `.xx' roff macro to take care of
the output typesetting. This is the default output format when GNU
extensions are disabled. Option `-M' might be used to change `xx'
to another macro name.
In this output format, each non-graphical character, like newline
and tab, is merely changed to exactly one space, with no special
attempt to compress consecutive spaces. Each quote character: `"'
is doubled so it will be correctly processed by `nroff' or `troff'.
`-T'
`--format=tex'
Choose an output format suitable for TeX processing. Each output
line will look like:
\xx {TAIL}{BEFORE}{KEYWORD}{AFTER}{HEAD}{REF}
so it will be possible to write write a `\xx' definition to take
care of the output typesetting. Note that when references are not
being produced, that is, neither option `-A' nor option `-r' is
selected, the last parameter of each `\xx' call is inhibited.
Option `-M' might be used to change `xx' to another macro name.
In this output format, some special characters, like `$', `%',
`&', `#' and `_' are automatically protected with a backslash.
Curly brackets `{', `}' are also protected with a backslash, but
also enclosed in a pair of dollar signs to force mathematical
mode. The backslash itself produces the sequence `\backslash{}'.
Circumflex and tilde diacritics produce the sequence `^\{ }' and
`~\{ }' respectively. Other diacriticized characters of the
underlying character set produce an appropriate TeX sequence as
far as possible. The other non-graphical characters, like newline
and tab, and all others characters which are not part of ASCII,
are merely changed to exactly one space, with no special attempt
to compress consecutive spaces. Let me know how to improve this
special character processing for TeX.

File: ptx.info, Node: Compatibility, Prev: Invoking ptx, Up: Top
The GNU extensions to `ptx'
***************************
This version of `ptx' contains a few features which do not exist in
System V `ptx'. These extra features are suppressed by using the `-G'
command line option, unless overridden by other command line options.
Some GNU extensions cannot be recovered by overriding, so the simple
rule is to avoid `-G' if you care about GNU extensions. Here are the
differences between this program and System V `ptx'.
* This program can read many input files at once, it always writes
the resulting concordance on standard output. On the other end,
System V `ptx' reads only one file and produce the result on
standard output or, if a second FILE parameter is given on the
command, to that FILE.
Having output parameters not introduced by options is a quite
dangerous practice which GNU avoids as far as possible. So, for
using `ptx' portably between GNU and System V, you should pay
attention to always use it with a single input file, and always
expect the result on standard output. You might also want to
automatically configure in a `-G' option to `ptx' calls in
products using `ptx', if the configurator finds that the installed
`ptx' accepts `-G'.
* The only options available in System V `ptx' are options `-b',
`-f', `-g', `-i', `-o', `-r', `-t' and `-w'. All other options
are GNU extensions and are not repeated in this enumeration.
Moreover, some options have a slightly different meaning when GNU
extensions are enabled, as explained below.
* By default, concordance output is not formatted for `troff' or
`nroff'. It is rather formatted for a dumb terminal. `troff' or
`nroff' output may still be selected through option `-O'.
* Unless `-R' option is used, the maximum reference width is
subtracted from the total output line width. With GNU extensions
disabled, width of references is not taken into account in the
output line width computations.
* All 256 characters, even `NUL's, are always read and processed from
input file with no adverse effect, even if GNU extensions are
disabled. However, System V `ptx' does not accept 8-bit
characters, a few control characters are rejected, and the tilda
`~' is condemned.
* Input line length is only limited by available memory, even if GNU
extensions are disabled. However, System V `ptx' processes only
the first 200 characters in each line.
* The break (non-word) characters default to be every character
except all letters of the underlying character set, diacriticized
or not. When GNU extensions are disabled, the break characters
default to space, tab and newline only.
* The program makes better use of output line width. If GNU
extensions are disabled, the program rather tries to imitate
System V `ptx', but still, there are some slight disposition
glitches this program does not completely reproduce.
* The user can specify both an Ignore file and an Only file. This
is not allowed with System V `ptx'.

Tag Table:
Node: Top939
Node: Invoking ptx2298
Node: General options5025
Node: Charset selection5639
Node: Input processing6514
Node: Output formatting12205
Node: Compatibility18737

End Tag Table