m4: Operation modes
2.1 Command line options for operation modes
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Several options control the overall operation of 'm4':
'--help'
Print a help summary on standard output, then immediately exit 'm4'
without reading any input files or performing any other actions.
'--version'
Print the version number of the program on standard output, then
immediately exit 'm4' without reading any input files or performing
any other actions.
'-E'
'--fatal-warnings'
Controls the effect of warnings. If unspecified, then execution
continues and exit status is unaffected when a warning is printed.
If specified exactly once, warnings become fatal; when one is
issued, execution continues, but the exit status will be non-zero.
If specified multiple times, then execution halts with non-zero
status the first time a warning is issued. The introduction of
behavior levels is new to M4 1.4.9; for behavior consistent with
earlier versions, you should specify '-E' twice.
'-i'
'--interactive'
'-e'
Makes this invocation of 'm4' interactive. This means that all
output will be unbuffered, and interrupts will be ignored. The
spelling '-e' exists for compatibility with other 'm4'
implementations, and issues a warning because it may be withdrawn
in a future version of GNU M4.
'-P'
'--prefix-builtins'
Internally modify _all_ builtin macro names so they all start with
the prefix 'm4_'. For example, using this option, one should write
'm4_define' instead of 'define', and 'm4___file__' instead of
'__file__'. This option has no effect if '-R' is also specified.
'-Q'
'--quiet'
'--silent'
Suppress warnings, such as missing or superfluous arguments in
macro calls, or treating the empty string as zero.
'--warn-macro-sequence[=REGEXP]'
Issue a warning if the regular expression REGEXP has a non-empty
match in any macro definition (either by 'define' or 'pushdef').
Empty matches are ignored; therefore, supplying the empty string as
REGEXP disables any warning. If the optional REGEXP is not
supplied, then the default regular expression is
'\$\({[^}]*}\|[0-9][0-9]+\)' (a literal '$' followed by multiple
digits or by an open brace), since these sequences will change
semantics in the default operation of GNU M4 2.0 (due to a change
in how more than 9 arguments in a macro definition will be handled,
⇒Arguments). Providing an alternate regular expression can
provide a useful reverse lookup feature of finding where a macro is
defined to have a given definition.
'-W REGEXP'
'--word-regexp=REGEXP'
Use REGEXP as an alternative syntax for macro names. This
experimental option will not be present in all GNU 'm4'
implementations (⇒Changeword).
Info Catalog
m4: Invoking m4
m4: Preprocessor features