m4: Operation modes
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1 2.1 Command line options for operation modes
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1 Several options control the overall operation of 'm4':
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1 '--help'
1 Print a help summary on standard output, then immediately exit 'm4'
1 without reading any input files or performing any other actions.
1
1 '--version'
1 Print the version number of the program on standard output, then
1 immediately exit 'm4' without reading any input files or performing
1 any other actions.
1
1 '-E'
1 '--fatal-warnings'
1 Controls the effect of warnings. If unspecified, then execution
1 continues and exit status is unaffected when a warning is printed.
1 If specified exactly once, warnings become fatal; when one is
1 issued, execution continues, but the exit status will be non-zero.
1 If specified multiple times, then execution halts with non-zero
1 status the first time a warning is issued. The introduction of
1 behavior levels is new to M4 1.4.9; for behavior consistent with
1 earlier versions, you should specify '-E' twice.
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1 '-i'
1 '--interactive'
1 '-e'
1 Makes this invocation of 'm4' interactive. This means that all
1 output will be unbuffered, and interrupts will be ignored. The
1 spelling '-e' exists for compatibility with other 'm4'
1 implementations, and issues a warning because it may be withdrawn
1 in a future version of GNU M4.
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1 '-P'
1 '--prefix-builtins'
1 Internally modify _all_ builtin macro names so they all start with
1 the prefix 'm4_'. For example, using this option, one should write
1 'm4_define' instead of 'define', and 'm4___file__' instead of
1 '__file__'. This option has no effect if '-R' is also specified.
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1 '-Q'
1 '--quiet'
1 '--silent'
1 Suppress warnings, such as missing or superfluous arguments in
1 macro calls, or treating the empty string as zero.
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1 '--warn-macro-sequence[=REGEXP]'
1 Issue a warning if the regular expression REGEXP has a non-empty
1 match in any macro definition (either by 'define' or 'pushdef').
1 Empty matches are ignored; therefore, supplying the empty string as
1 REGEXP disables any warning. If the optional REGEXP is not
1 supplied, then the default regular expression is
1 '\$\({[^}]*}\|[0-9][0-9]+\)' (a literal '$' followed by multiple
1 digits or by an open brace), since these sequences will change
1 semantics in the default operation of GNU M4 2.0 (due to a change
1 in how more than 9 arguments in a macro definition will be handled,
1 ⇒Arguments). Providing an alternate regular expression can
1 provide a useful reverse lookup feature of finding where a macro is
1 defined to have a given definition.
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1 '-W REGEXP'
1 '--word-regexp=REGEXP'
1 Use REGEXP as an alternative syntax for macro names. This
1 experimental option will not be present in all GNU 'm4'
1 implementations (⇒Changeword).
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