GNU Info

(m4.info)Changecom

---

Next: Changeword Prev: Changequote Up: Input Control

---

Enter node , (file) or (file)node

Changing comment delimiters
===========================

   The default comment delimiters can be changed with the builtin macro
`changecom':

     changecom(opt START, opt END)

where START is the new start-comment delimiter and END is the new
end-comment delimiter.  If any of the arguments are void, the default
comment delimiters (`#' and newline) are used instead of the void
arguments.  The comment delimiters can be of any length.

   The expansion of `changecom' is void.

     define(`comment', `COMMENT')
     =>
     # A normal comment
     =># A normal comment
     changecom(`/*', `*/')
     =>
     # Not a comment anymore
     =># Not a COMMENT anymore
     But: /* this is a comment now */ while this is not a comment
     =>But: /* this is a comment now */ while this is not a COMMENT

   Note how comments are copied to the output, much as if they were
quoted strings.  If you want the text inside a comment expanded, quote
the start comment delimiter.

   Calling `changecom' without any arguments disables the commenting
mechanism completely.

     define(`comment', `COMMENT')
     =>
     changecom
     =>
     # Not a comment anymore
     =># Not a COMMENT anymore