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M4(1)				  User Commands 			   M4(1)

NAME
     m4 - macro processor

SYNOPSIS
     m4 [OPTION]... [FILE]...

DESCRIPTION
     Process  macros  in FILEs.  If no FILE or if FILE is `-', standard input is
     read.

     Mandatory or optional arguments to long options are mandatory  or	optional
     for short options too.

   Operation modes:
     --help
	    display this help and exit

     --version
	    output version information and exit

     -E, --fatal-warnings
	    once: warnings become errors, twice: stop execution at first error

     -i, --interactive
	    unbuffer output, ignore interrupts

     -P, --prefix-builtins
	    force a `m4_' prefix to all builtins

     -Q, --quiet, --silent
	    suppress some warnings for builtins

     --warn-macro-sequence[=REGEXP]
	    warn if macro definition matches REGEXP,

	    default \$\({[^}]*}\|[0-9][0-9]+\)

     -W, --word-regexp=REGEXP
	    use REGEXP for macro name syntax

   Preprocessor features:
     -D, --define=NAME[=VALUE]
	    define NAME as having VALUE, or empty

     -I, --include=DIRECTORY
	    append DIRECTORY to include path

     -s, --synclines
	    generate `#line NUM "FILE"' lines

     -U, --undefine=NAME
	    undefine NAME

   Limits control:
     -g, --gnu
	    override -G to re-enable GNU extensions

     -G, --traditional
	    suppress all GNU extensions

     -H, --hashsize=PRIME
	    set symbol lookup hash table size [65537]

     -L, --nesting-limit=NUMBER
	    change nesting limit, 0 for unlimited [0]

   Frozen state files:
     -F, --freeze-state=FILE
	    produce a frozen state on FILE at end

     -R, --reload-state=FILE
	    reload a frozen state from FILE at start

   Debugging:
     -d, --debug[=FLAGS]
	    set debug level (no FLAGS implies `aeq')

     --debugfile[=FILE]
	    redirect  debug and trace output to FILE (default stderr, discard if
	    empty string)

     -l, --arglength=NUM
	    restrict macro tracing size

     -t, --trace=NAME
	    trace NAME when it is defined

   FLAGS is any of:
     a	    show actual arguments

     c	    show before collect, after collect and after call

     e	    show expansion

     f	    say current input file name

     i	    show changes in input files

     l	    say current input line number

     p	    show results of path searches

     q	    quote values as necessary, with a or e flag

     t	    trace for all macro calls, not only traceon'ed

     x	    add a unique macro call id, useful with c flag

     V	    shorthand for all of the above flags

     If defined, the environment variable `M4PATH' is a colon-separated list  of
     directories included after any specified by `-I'.

     Exit  status  is  0  for success, 1 for failure, 63 for frozen file version
     mismatch, or whatever value was passed to the m4exit macro.

AUTHOR
     Written by Rene' Seindal.

REPORTING BUGS
     Report bugs to: bug-m4@gnu.org
     GNU M4 home page: <https://www.gnu.org/software/m4/>
     General help using GNU software: <https://www.gnu.org/gethelp/>

COPYRIGHT
     Copyright (C) 2026 Free Software Foundation, Inc.	License GPLv3+: GNU  GPL
     version 3 or later <https://gnu.org/licenses/gpl.html>.
     This  is  free software: you are free to change and redistribute it.  There
     is NO WARRANTY, to the extent permitted by law.

SEE ALSO
     The full documentation for m4 is maintained as a Texinfo  manual.	 If  the
     info and m4 programs are properly installed at your site, the command

	    info m4

     should give you access to the complete manual.

GNU M4 1.4.21			  February 2026 			   M4(1)
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