m4: Debugging options
2.5 Command line options for debugging
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Finally, there are several options for aiding in debugging 'm4' scripts.
'-d[FLAGS]'
'--debug[=FLAGS]'
Set the debug-level according to the flags FLAGS. The debug-level
controls the format and amount of information presented by the
debugging functions. ⇒Debug Levels, for more details on the
format and meaning of FLAGS. If omitted, FLAGS defaults to 'aeq'.
'--debugfile[=FILE]'
'-o FILE'
'--error-output=FILE'
Redirect 'dumpdef' output, debug messages, and trace output to the
named FILE. Warnings, error messages, and 'errprint' output are
still printed to standard error. If these options are not used, or
if FILE is unspecified (only possible for '--debugfile'), debug
output goes to standard error; if FILE is the empty string, debug
output is discarded. ⇒Debug Output, for more details. The
option '--debugfile' may be given more than once, and order is
significant with respect to file names. The spellings '-o' and
'--error-output' are misleading and inconsistent with other GNU
tools; for now they are silently accepted as synonyms of
'--debugfile' and only recognized once, but in a future version of
M4, using them will cause a warning to be issued.
'-l NUM'
'--arglength=NUM'
Restrict the size of the output generated by macro tracing to NUM
characters per trace line. If unspecified or zero, output is
unlimited. ⇒Debug Levels, for more details.
'-t NAME'
'--trace=NAME'
This enables tracing for the macro NAME, at any point where it is
defined. NAME need not be defined when this option is given. This
option may be given more than once, and order is significant with
respect to file names. ⇒Trace, for more details.