#!/usr/bin/perl
# reg.pl - Don Yang (uguu.org)
# Strip C comments using regular expressions.
#
# That regular expression is something, took me a while to figure out how
# to gobble one token at a time, because a naive global match tends overlap
# tokens.  Everything else should be straightforward.
#
# 06/17/01

for($input = join '', <>; $input;)
{
   # Get next token
   $input =~
      m!^ (" ((\\.)|[^\\"])*? ")  |    # Double quoted strings
          (' ((\\.)|[^\\'])*? ')  |    # Single quoted strings
          ((/\*)(.*?)(\*/) )      |    # Comments
          (.)                          # Every other character
       !osx;
   $token = $&;

   # Gobble input
   $input = substr $input, length $token;

   # Replace comments with spaces
   if( $token =~ m!^/.+/$!os )
   {
      $token =~ s/[^\s\n]/ /gos;
   }

   # Print
   print $token;
}