#!/usr/bin/perl -w

use strict;

# Run a program, captures its output, and return all the lines
sub Run($)
{
   my ($prog) = @_;
   my @lines = `$prog`;
   if( $? != 0 )
   {
      die "$prog failed: $?\n";
   }
   unless( scalar @lines )
   {
      die "$prog produced no output\n";
   }
   chomp foreach @lines;
   return @lines;
}

# Scale a single line by duplicating characters
sub Expand($$)
{
   my ($line, $factor) = @_;
   my $result = "";

   foreach my $c (unpack 'C*', $line)
   {
      $result .= chr($c) x $factor;
   }
   return $result;
}



die "$0 <cat1> <cat2> <cat3>\n" unless $#ARGV == 2;

my @cat1 = Run($ARGV[0]);
my @cat2 = Run($ARGV[1]);
my @cat3 = Run($ARGV[2]);
my $line_count = scalar @cat1;
if( $line_count > scalar @cat2 ) { $line_count = scalar @cat2; }
if( $line_count > scalar @cat3 ) { $line_count = scalar @cat3; }

for(my $i = 0; $i < $line_count; $i++)
{
   if( Expand($cat1[$i], 2) ne $cat2[$i] )
   {
      die "Line $i mismatched\n";
   }
   if( Expand($cat1[$i], 3) ne $cat3[$i] )
   {
      die "Line $i mismatched\n";
   }
}

# All good
exit 0;