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 [509]

       -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  ©  2021  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 1.4.19                                       May 2021                                               M4(1)