File: m4.info,  Node: Comments,  Next: Other tokens,  Prev: Quoted strings,  Up: Syntax

3.3 Comments in ‘m4’ input
==========================

Comments in ‘m4’ are normally delimited by the characters ‘#’ and
newline.  All characters between the comment delimiters are ignored, but
the entire comment (including the delimiters) is passed through to the
output--comments are _not_ discarded by ‘m4’.

   Comments cannot be nested, so the first newline after a ‘#’ ends the
comment.  The commenting effect of the begin-comment string can be
inhibited by quoting it.

     $ m4
     `quoted text' # `commented text'
     ⇒quoted text # `commented text'
     `quoting inhibits' `#' `comments'
     ⇒quoting inhibits # comments

   The comment delimiters can be changed to any string at any time,
using the builtin macro ‘changecom’.  *Note Changecom::, for more
information.