m4 − macro processor
m4 [OPTION]... [FILE]...
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 \$\({[^}]*}\|[0−9][0−9]+\)
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 |
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|
c |
show before collect, after collect and after call |
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|
e |
show expansion |
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|
f |
say current input file name |
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|
i |
show changes in input files |
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|
l |
say current input line number |
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|
p |
show results of path searches |
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q |
quote values as necessary, with a or e flag |
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|
t |
trace for all macro calls, not only traceon’ed |
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|
x |
add a unique macro call id, useful with c flag |
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|
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.
Written by Rene’ Seindal.
Report bugs to:
bug−m4@gnu.org
GNU M4 home page: <http://www.gnu.org/software/m4/>
General help using GNU software:
<http://www.gnu.org/gethelp/>
Copyright
© 2011 Free Software Foundation, Inc. License GPLv3+:
GNU GPL version 3 or later
<http://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.
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.