#!/usr/bin/perl
# xor.pl - Don Yang (uguu.org)
#
# 09/04/03

die "$0 <key>\n" unless $#ARGV == 0;

$key = $ARGV[0];
print STDERR "key = $key\n";

$err = 0;
%char = ();
while( $line = <STDIN> )
{
   $line =~ s/\s//g;
   $line =~ s!/M/sub/!/M/sub /!;
   $line =~ s!/k//!/k/ /!;
   foreach $i ($line =~ /./g)
   {
      $c = ord($i) ^ $key;
      if( $c <= 32 || $c > 126 )
      {
         $err++;
         $char{$i}++;
      }
      $c = chr($c);
      if( index('\\"$%', $c) >= 0 )
      {
         $err++;
         $char{$i}++;
      }
      print $c;
   }
   print "\n";
}
print STDERR "err = $err";
if( $err > 0 )
{
   foreach $i (sort {$a cmp $b} keys %char)
   {
      print STDERR " $i:$char{$i}";
   }
}
print STDERR "\n";