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.