1 #! perl -w

     2 use strict;

     3 

     4 my $element;

     5 my @union = ();

     6 my @intersection = ();

     7 my @difference = ();

     8 my %count = ();

     9 

    10 my $file1 = shift or die "Usage: $0 file1 file2\n";

    11 my $file2 = shift or die "Usage: $0 file1 file2\n";

    12 

    13 open FILE1, "<$file1" or die "ERROR: Can't read $file1";

    14 open FILE2, "<$file2" or die "ERROR: Can't read $file2";

    15 

    16 my @file1_content = <FILE1>;

    17 my @file2_content = <FILE2>;

    18 

    19 close FILE1;

    20 close FILE2;

    21 

    22 print "* Comparing $file1 and $file2\n";

    23 foreach $element (@file1_content, @file2_content) { $count{$element}++ }

    24 foreach $element (keys %count) {

    25     push @union, $element;

    26     push @{ $count{$element} > 1 ? \@intersection : \@difference }, $element;

    27 }

    28 

    29 if (@difference > 0) {

    30     foreach (@difference){

    31         print $_;

    32     }

    33 } else {

    34     print "* Files are identical\n";

    35 }