Linux Cross Reference
Linux/scripts/checkincludes.pl

   #!/usr/bin/perl
   #
   # checkincludes: Find files included more than once in (other) files.
   # Copyright abandoned, 2000, Niels Kristian Bech Jensen <nkbj@image.dk>.
   
   foreach $file (@ARGV) {
           open(FILE, $file) or die "Cannot open $file: $!.\n";
   
           my %includedfiles = ();
  
          while (<FILE>) {
                  if (m/^\s*#\s*include\s*[<"](\S*)[>"]/o) {
                          ++$includedfiles{$1};
                  }
          }
          
          foreach $filename (keys %includedfiles) {
                  if ($includedfiles{$filename} > 1) {
                          print "$file: $filename is included more than once.\n";
                  }
          }
  
          close(FILE);
  }