(m4.info)Invoking m4

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2 Invoking 'm4'
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The format of the 'm4' command is:

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

   All options begin with '-', or if long option names are used, with
'--'.  A long option name need not be written completely, any
unambiguous prefix is sufficient.  POSIX requires 'm4' to recognize
arguments intermixed with files, even when 'POSIXLY_CORRECT' is set in
the environment.  Most options take effect at startup regardless of
their position, but some are documented below as taking effect after any
files that occurred earlier in the command line.  The argument '--' is a
marker to denote the end of options.

   With short options, options that do not take arguments may be
combined into a single command line argument with subsequent options,
options with mandatory arguments may be provided either as a single
command line argument or as two arguments, and options with optional
arguments must be provided as a single argument.  In other words, 'm4
-QPDfoo -d a -df' is equivalent to 'm4 -Q -P -D foo -d -df -- ./a',
although the latter form is considered canonical.

   With long options, options with mandatory arguments may be provided
with an equal sign ('=') in a single argument, or as two arguments, and
options with optional arguments must be provided as a single argument.
In other words, 'm4 --def foo --debug a' is equivalent to 'm4
--define=foo --debug= -- ./a', although the latter form is considered
canonical (not to mention more robust, in case a future version of 'm4'
introduces an option named '--default').

   'm4' understands the following options, grouped by functionality.

Operation modes

Command line options for operation modes

Preprocessor features

Command line options for preprocessor features

Limits control

Command line options for limits control

Frozen state

Command line options for frozen state

Debugging options

Command line options for debugging

Command line files

Specifying input files on the command line