while( <DATA> ){
  if( /^\s*(\Winclude\s+\W([^g]\w+\.?\w*)\W)/ ){
    print "Match: $1 at line $.$/"
  }
}


__DATA__

#include "abc.h"
#include "gbc.h"
#include <cbc.h>
#include <gcg.h>

__END__

STDOUT:
Match: #include "abc.h" at line 2
Match: #include <cbc.h> at line 4