Merge differences and correct the manual page.
This commit is contained in:
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71e398c525
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=95059
453
usr.bin/m4/m4.1
453
usr.bin/m4/m4.1
@ -1,216 +1,381 @@
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.\" @(#) $OpenBSD: m4.1,v 1.24 2002/04/18 18:57:23 espie Exp $
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.\" $FreeBSD$
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.\"
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.\" @(#) $FreeBSD$
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.\"
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.Dd April 17, 2002
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.Dd January 26, 1993
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.Dt M4 1
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.Os
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.Sh NAME
|
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.Nm m4
|
||||
.Nd macro language processor
|
||||
.Sh SYNOPSIS
|
||||
.Nm
|
||||
.Nm m4
|
||||
.Op Fl d Ar flags
|
||||
.Op Fl t Ar name
|
||||
.Op Fl g
|
||||
.Oo
|
||||
.Fl D Ar name Ns Op Ar =value
|
||||
.Fl D Ns Ar name Ns Op Ar =value
|
||||
.Oc
|
||||
.Op Fl U Ar name
|
||||
.Op Ar filename
|
||||
\|.\|.\|.
|
||||
.Op Fl U Ns Ar name
|
||||
.Op Fl I Ar dirname
|
||||
.Sh DESCRIPTION
|
||||
The
|
||||
.Nm
|
||||
.Nm m4
|
||||
utility is a macro processor that can be used as a front end to any
|
||||
language (e.g., C, ratfor, fortran, lex, and yacc).
|
||||
Each of the argument files is processed in order.
|
||||
If there are no files, or if a filename is \`-\', the standard input is read.
|
||||
The processed text is sent to the standard output.
|
||||
.Nm m4
|
||||
reads from the standard input and writes
|
||||
the processed text to the standard output.
|
||||
.Pp
|
||||
Macro calls have the form name(argument1[, argument2, ...,] argumentN).
|
||||
Macro calls have the form name(argument1[, argument2, ..., argumentN]).
|
||||
.Pp
|
||||
There cannot be any space following the macro name and the open
|
||||
parentheses '('. If the macro name is not followed by an open
|
||||
parentheses it is processed with no arguments.
|
||||
parenthesis
|
||||
.Pq Ql ( .
|
||||
If the macro name is not followed by an open
|
||||
parenthesis it is processed with no arguments.
|
||||
.Pp
|
||||
Macro names consist of a leading alphabetic or underscore
|
||||
possibly followed by alphanumeric or underscore characters, therefore
|
||||
valid macro names match this pattern [a-zA-Z_][a-zA-Z0-9_]*.
|
||||
possibly followed by alphanumeric or underscore characters, e.g.,
|
||||
valid macro names match the pattern
|
||||
.Dq [a-zA-Z_][a-zA-Z0-9_]* .
|
||||
.Pp
|
||||
In arguments to macros, leading unquoted space, tab and newline
|
||||
characters are ignored. To quote strings use left and right single
|
||||
quotes (e.g., ` this is a string with a leading space'). You can change
|
||||
the quote characters with the changequote built-in macro.
|
||||
In arguments to macros, leading unquoted space, tab, and newline
|
||||
.Pq Ql \en
|
||||
characters are ignored.
|
||||
To quote strings, use left and right single
|
||||
quotes (e.g.,
|
||||
.Sq \ this is a string with a leading space ) .
|
||||
You can change the quote characters with the
|
||||
.Ic changequote
|
||||
built-in macro.
|
||||
.Pp
|
||||
Most built-ins don't make any sense without arguments, and hence are not
|
||||
recognized as special when not followed by an open parenthesis.
|
||||
.Pp
|
||||
The options are as follows:
|
||||
.Bl -tag -width "-Dname[=value]xxx"
|
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.It Fl s
|
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Emit
|
||||
.Em #line
|
||||
directives for
|
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.Xr cpp 1 .
|
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.It Fl D Ar name Ns Oo
|
||||
.Bl -tag -width Ds
|
||||
.It Fl D Ns Ar name Ns Oo
|
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.Ar =value
|
||||
.Oc
|
||||
Define the symbol
|
||||
.Ar name
|
||||
to have some value (or NULL).
|
||||
.It Fl "U" Ar "name"
|
||||
to have some value (or
|
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.Dv NULL ) .
|
||||
.It Fl "U" Ns Ar "name"
|
||||
Undefine the symbol
|
||||
.Ar name .
|
||||
.It Fl I Ar "dirname"
|
||||
Add directory
|
||||
.Ar dirname
|
||||
to the include path.
|
||||
.It Fl d Ar "flags"
|
||||
Set trace flags.
|
||||
.Ar flags
|
||||
may hold the following:
|
||||
.Bl -tag -width Ds
|
||||
.It Ar a
|
||||
print macro arguments.
|
||||
.It Ar c
|
||||
print macro expansion over several lines.
|
||||
.It Ar e
|
||||
print result of macro expansion.
|
||||
.It Ar f
|
||||
print filename location.
|
||||
.It Ar l
|
||||
print line number.
|
||||
.It Ar q
|
||||
quote arguments and expansion with the current quotes.
|
||||
.It Ar t
|
||||
start with all macros traced.
|
||||
.It Ar x
|
||||
number macro expansions.
|
||||
.It Ar V
|
||||
turn on all options.
|
||||
.El
|
||||
.Pp
|
||||
By default, trace is set to
|
||||
.Qq eq .
|
||||
.It Fl t Ar macro
|
||||
Turn tracing on for
|
||||
.Ar macro .
|
||||
.It Fl g
|
||||
Activate GNU-m4 compatibility mode.
|
||||
In this mode, changequote with
|
||||
two empty parameters deactivates quotes, translit handles simple character
|
||||
ranges (e.g., a-z), regular expressions mimic emacs behavior,
|
||||
and the number of diversions is unlimited.
|
||||
.El
|
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.Sh SYNTAX
|
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.Nm
|
||||
provides the following built-in macros. They may be
|
||||
redefined, losing their original meaning.
|
||||
Return values are NULL unless otherwise stated.
|
||||
.Nm m4
|
||||
provides the following built-in macros.
|
||||
They may be redefined, losing their original meaning.
|
||||
Return values are null unless otherwise stated.
|
||||
.Bl -tag -width changequotexxx
|
||||
.It changecom
|
||||
Change the start and end comment sequences. The default is
|
||||
the pound sign `#' and the newline character. With no arguments
|
||||
comments are turned off. The maximum length for a comment marker is
|
||||
five characters.
|
||||
.It changequote
|
||||
.It Ic builtin
|
||||
Calls a built-in by its name, overriding possible redefinitions.
|
||||
.It Ic changecom
|
||||
Change the start and end comment sequences.
|
||||
The default is the pound sign
|
||||
.Pq Ql #
|
||||
and the newline character.
|
||||
With no arguments comments are turned off.
|
||||
The maximum length for a comment marker is five characters.
|
||||
.It Ic changequote
|
||||
Defines the quote symbols to be the first and second arguments.
|
||||
Note, only the first character of each argument is used. If no arguments are
|
||||
The symbols may be up to five characters long.
|
||||
If no arguments are
|
||||
given it restores the default open and close single quotes.
|
||||
.It decr
|
||||
Decrements the argument by 1. The argument must be a valid numeric string.
|
||||
.It define
|
||||
.It Ic decr
|
||||
Decrements the argument by 1.
|
||||
The argument must be a valid numeric string.
|
||||
.It Ic define
|
||||
Define a new macro named by the first argument to have the
|
||||
value of the second argument. Each occurrence of $n (where n
|
||||
is 0 through 9) is replaced by the n'th argument. $0 is the name
|
||||
of the calling macro. Undefined arguments are replaced by a
|
||||
NULL string. $# is replaced by the number of arguments; $*
|
||||
is replaced by all arguments comma separated; $@ is the same
|
||||
as $* but all arguments are quoted against further expansion.
|
||||
.It defn
|
||||
Returns the quoted definition for each argument. This can be used to rename
|
||||
value of the second argument.
|
||||
Each occurrence of
|
||||
.Ql $n
|
||||
(where
|
||||
.Ar n
|
||||
is 0 through 9) is replaced by the
|
||||
.Ar n Ns 'th
|
||||
argument.
|
||||
.Ql $0
|
||||
is the name of the calling macro.
|
||||
Undefined arguments are replaced by a null string.
|
||||
.Ql $#
|
||||
is replaced by the number of arguments;
|
||||
.Ql $*
|
||||
is replaced by all arguments comma separated;
|
||||
.Ql $@
|
||||
is the same as
|
||||
.Ql $*
|
||||
but all arguments are quoted against further expansion.
|
||||
.It Ic defn
|
||||
Returns the quoted definition for each argument.
|
||||
This can be used to rename
|
||||
macro definitions (even for built-in macros).
|
||||
.It divert
|
||||
.It Ic divert
|
||||
There are 10 output queues (numbered 0-9).
|
||||
At the end of processing
|
||||
.Nm
|
||||
.Nm m4
|
||||
concatenates all the queues in numerical order to produce the
|
||||
final output. Initially the output queue is 0. The divert
|
||||
final output.
|
||||
Initially the output queue is 0.
|
||||
The divert
|
||||
macro allows you to select a new output queue (an invalid argument
|
||||
passed to divert causes output to be discarded).
|
||||
.It divnum
|
||||
.It Ic divnum
|
||||
Returns the current output queue number.
|
||||
.It dnl
|
||||
.It Ic dnl
|
||||
Discard input characters up to and including the next newline.
|
||||
.It dumpdef
|
||||
.It Ic dumpdef
|
||||
Prints the names and definitions for the named items, or for everything
|
||||
if no arguments are passed.
|
||||
.It errprint
|
||||
.It Ic errprint
|
||||
Prints the first argument on the standard error output stream.
|
||||
.It eval
|
||||
.It Ic esyscmd
|
||||
Pass its first argument to a shell and returns the shell's standard output.
|
||||
Note that the shell shares its standard input and standard error with
|
||||
.Nm
|
||||
.It Ic eval
|
||||
Computes the first argument as an arithmetic expression using 32-bit
|
||||
arithmetic. Operators are the standard C ternary, arithmetic, logical,
|
||||
shift, relational, bitwise, and parentheses operators. You can specify
|
||||
octal, decimal, and hexadecimal numbers as in C. The second argument (if
|
||||
any) specifies the radix for the result and the third argument (if
|
||||
any) specifies the minimum number of digits in the result.
|
||||
.It expr
|
||||
This is an alias for eval.
|
||||
.It ifdef
|
||||
arithmetic.
|
||||
Operators are the standard C ternary, arithmetic, logical,
|
||||
shift, relational, bitwise, and parentheses operators.
|
||||
You can specify
|
||||
octal, decimal, and hexadecimal numbers as in C.
|
||||
The second argument (if any)
|
||||
specifies the radix for the result and the third argument (if any)
|
||||
specifies the minimum number of digits in the result.
|
||||
.It Ic expr
|
||||
This is an alias for
|
||||
.Ic eval .
|
||||
.It Ic ifdef
|
||||
If the macro named by the first argument is defined then return the second
|
||||
argument, otherwise the third. If there is no third argument,
|
||||
the value is NULL. The word `unix' is predefined.
|
||||
.It ifelse
|
||||
If the first argument matches the second argument then ifelse returns
|
||||
the third argument. If the match fails the three arguments are
|
||||
argument, otherwise the third.
|
||||
If there is no third argument, the value is
|
||||
.Dv NULL .
|
||||
The word
|
||||
.Qq unix
|
||||
is predefined.
|
||||
.It Ic ifelse
|
||||
If the first argument matches the second argument then
|
||||
.Ic ifelse
|
||||
returns
|
||||
the third argument.
|
||||
If the match fails the three arguments are
|
||||
discarded and the next three arguments are used until there is
|
||||
zero or one arguments left, either this last argument or NULL is
|
||||
returned if no other matches were found.
|
||||
.It include
|
||||
zero or one arguments left, either this last argument or
|
||||
.Dv NULL
|
||||
is returned if no other matches were found.
|
||||
.It Ic include
|
||||
Returns the contents of the file specified in the first argument.
|
||||
If the file is not found as is, look through the include path:
|
||||
first the directories specified with
|
||||
.Fl I
|
||||
on the command line, then the environment variable
|
||||
.Ev M4PATH ,
|
||||
as a colon-separated list of directories.
|
||||
Include aborts with an error message if the file cannot be included.
|
||||
.It incr
|
||||
Increments the argument by 1. The argument must be a valid numeric string.
|
||||
.It index
|
||||
.It Ic incr
|
||||
Increments the argument by 1.
|
||||
The argument must be a valid numeric string.
|
||||
.It Ic index
|
||||
Returns the index of the second argument in the first argument (e.g.,
|
||||
index(the quick brown fox jumped, fox) returns 16). If the second
|
||||
argument is not found index returns -1.
|
||||
.It len
|
||||
Returns the number of characters in the first argument. Extra arguments
|
||||
.Ic index(the quick brown fox jumped, fox)
|
||||
returns 16).
|
||||
If the second
|
||||
argument is not found index returns \-1.
|
||||
.It Ic indir
|
||||
Indirectly calls the macro whose name is passed as the first arguments,
|
||||
with the remaining arguments passed as first, ... arguments.
|
||||
.It Ic len
|
||||
Returns the number of characters in the first argument.
|
||||
Extra arguments
|
||||
are ignored.
|
||||
.It m4exit
|
||||
.It Ic m4exit
|
||||
Immediately exits with the return value specified by the first argument,
|
||||
0 if none.
|
||||
.It m4wrap
|
||||
Allows you to define what happens at the final EOF, usually for cleanup
|
||||
purposes (e.g., m4wrap("cleanup(tempfile)") causes the macro cleanup to be
|
||||
invoked after all other processing is done.)
|
||||
.It maketemp
|
||||
Translates the string XXXXX in the first argument with the current process
|
||||
ID leaving other characters alone. This can be used to create unique
|
||||
.It Ic m4wrap
|
||||
Allows you to define what happens at the final
|
||||
.Dv EOF ,
|
||||
usually for cleanup purposes (e.g.,
|
||||
.Ic m4wrap("cleanup(tempfile)")
|
||||
causes the macro cleanup to be
|
||||
invoked after all other processing is done).
|
||||
.It Ic maketemp
|
||||
Translates the string
|
||||
.Dq XXXXX
|
||||
in the first argument with the current process
|
||||
ID leaving other characters alone.
|
||||
This can be used to create unique
|
||||
temporary file names.
|
||||
.It paste
|
||||
.It Ic paste
|
||||
Includes the contents of the file specified by the first argument without
|
||||
any macro processing. Aborts with an error message if the file cannot be
|
||||
any macro processing.
|
||||
Aborts with an error message if the file cannot be
|
||||
included.
|
||||
.It popdef
|
||||
Restores the pushdef'ed definition for each argument.
|
||||
.It pushdef
|
||||
Takes the same arguments as define, but it saves the definition on a
|
||||
stack for later retrieval by popdef.
|
||||
.It shift
|
||||
.It Ic patsubst
|
||||
Substitutes a regular expression in a string with a replacement string.
|
||||
Usual substitution patterns apply: an ampersand
|
||||
.Pq Ql &
|
||||
is replaced by the string matching the regular expression.
|
||||
The string
|
||||
.Ql \e# ,
|
||||
where
|
||||
.Ql #
|
||||
is a digit, is replaced by the corresponding back-reference.
|
||||
.It Ic popdef
|
||||
Restores the
|
||||
.Ic pushdef Ns ed
|
||||
definition for each argument.
|
||||
.It Ic pushdef
|
||||
Takes the same arguments as
|
||||
.Ic define ,
|
||||
but it saves the definition on a
|
||||
stack for later retrieval by
|
||||
.Ic popdef .
|
||||
.It Ic regexp
|
||||
Finds a regular expression in a string.
|
||||
If no further arguments are given,
|
||||
it returns the first match position or \-1 if no match.
|
||||
If a third argument
|
||||
is provided, it returns the replacement string, with sub-patterns replaced.
|
||||
.It Ic shift
|
||||
Returns all but the first argument, the remaining arguments are
|
||||
quoted and pushed back with commas in between. The quoting
|
||||
quoted and pushed back with commas in between.
|
||||
The quoting
|
||||
nullifies the effect of the extra scan that will subsequently be
|
||||
performed.
|
||||
.It sinclude
|
||||
Similar to include, except it ignores any errors.
|
||||
.It spaste
|
||||
Similar to paste, except it ignores any errors.
|
||||
.It substr
|
||||
.It Ic sinclude
|
||||
Similar to
|
||||
.Ic include ,
|
||||
except it ignores any errors.
|
||||
.It Ic spaste
|
||||
Similar to
|
||||
.Ic paste ,
|
||||
except it ignores any errors.
|
||||
.It Ic substr
|
||||
Returns a substring of the first argument starting at the offset specified
|
||||
by the second argument and the length specified by the third argument.
|
||||
If no third argument is present it returns the rest of the string.
|
||||
.It syscmd
|
||||
Passes the first argument to the shell. Nothing is returned.
|
||||
.It sysval
|
||||
Returns the return value from the last syscmd.
|
||||
.It translit
|
||||
.It Ic syscmd
|
||||
Passes the first argument to the shell.
|
||||
Nothing is returned.
|
||||
.It Ic sysval
|
||||
Returns the return value from the last
|
||||
.Ic syscmd .
|
||||
.It Ic traceon
|
||||
Enables tracing of macro expansions for the given arguments, or for all
|
||||
macros if no argument is given.
|
||||
.It Ic traceoff
|
||||
Disables tracing of macro expansions for the given arguments, or for all
|
||||
macros if no argument is given.
|
||||
.It Ic translit
|
||||
Transliterate the characters in the first argument from the set
|
||||
given by the second argument to the set given by the third. You cannot
|
||||
use
|
||||
given by the second argument to the set given by the third.
|
||||
You cannot use
|
||||
.Xr tr 1
|
||||
style abbreviations.
|
||||
.It undefine
|
||||
Removes the definition for the macro specified by the first argument.
|
||||
.It undivert
|
||||
.It Ic undefine
|
||||
Removes the definition for the macros specified by its arguments.
|
||||
.It Ic undivert
|
||||
Flushes the named output queues (or all queues if no arguments).
|
||||
.It unix
|
||||
.It Ic unix
|
||||
A pre-defined macro for testing the OS platform.
|
||||
.It Ic __line__
|
||||
Returns the current file's line number.
|
||||
.It Ic __file__
|
||||
Returns the current file's name.
|
||||
.El
|
||||
.Sh DIAGNOSTICS
|
||||
.Ex -std
|
||||
.Pp
|
||||
The exit status can be specified by the input file using the
|
||||
.Em m4exit
|
||||
macro.
|
||||
.Sh "SEE ALSO"
|
||||
.Xr cpp 1
|
||||
.Sh STANDARDS
|
||||
The
|
||||
.Sh COMPATIBILITY
|
||||
.Nm
|
||||
utility is compatible with the
|
||||
.St -p1003.1-2001
|
||||
specification with the exception of the
|
||||
.Em traceon
|
||||
and
|
||||
.Em traceoff
|
||||
built-in macros, which are not implemented.
|
||||
follows the Single Unix 2 specification, along with a few extensions taken
|
||||
from
|
||||
.Nm gnu-m4 .
|
||||
.Pp
|
||||
The
|
||||
.Em expr ,
|
||||
.Em paste ,
|
||||
.Em spaste
|
||||
and
|
||||
.Em unix
|
||||
built-in macros are extensions to the standard.
|
||||
.Fl s
|
||||
option
|
||||
.Po
|
||||
.Xr cpp 1 's
|
||||
#line directives
|
||||
.Pc
|
||||
is currently not supported.
|
||||
Flags
|
||||
.Fl I ,
|
||||
.Fl d ,
|
||||
.Fl t
|
||||
are non-standard.
|
||||
.Pp
|
||||
The output format of tracing and of
|
||||
.Ic dumpdef
|
||||
are not specified in any standard,
|
||||
are likely to change and should not be relied upon.
|
||||
The current format of tracing is closely modelled on
|
||||
.Nm gnu-m4 ,
|
||||
to allow
|
||||
.Nm autoconf
|
||||
to work.
|
||||
.Pp
|
||||
For portability, one should not use the macros
|
||||
.Ic builtin ,
|
||||
.Ic esycmd ,
|
||||
.Ic expr ,
|
||||
.Ic indir ,
|
||||
.Ic paste ,
|
||||
.Ic patsubst ,
|
||||
.Ic regexp ,
|
||||
.Ic spaste ,
|
||||
.Ic unix ,
|
||||
.Ic __line__ ,
|
||||
.Ic __file__ .
|
||||
.Pp
|
||||
All builtins do expand without arguments in many other
|
||||
.Nm m4 .
|
||||
.Pp
|
||||
Many other
|
||||
.Nm
|
||||
have dire size limitations with respect to buffer sizes.
|
||||
.Sh AUTHORS
|
||||
.An Ozan Yigit Aq oz@sis.yorku.ca
|
||||
and
|
||||
.An Richard A. O'Keefe Aq ok@goanna.cs.rmit.OZ.AU
|
||||
.Sh BUGS
|
||||
The tracing macros are not implemented.
|
||||
Ozan Yigit <oz@sis.yorku.ca> and Richard A. O'Keefe (ok@goanna.cs.rmit.OZ.AU).
|
||||
GNU-m4 compatibility extensions by Marc Espie <espie@cvs.openbsd.org>.
|
||||
|
Loading…
Reference in New Issue
Block a user