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 © 2025 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 1.4.20 May 2025 m4(1)
m4 1.4.20 - Generated Sat May 10 15:59:50 CDT 2025