Shell Programming and Scripting

$ cat inputfile1
1233
2345
3456
4444
7777
$ cat inputfile2
1244
2345
3456
9898
9999
$ cat script.pl
use warnings;
use strict;
 
my (%hash);
 
die qq|Usage: $0 <inputfile-1> <inputfile-2> <outputfile-1> <outputfile-2>\n| 
        unless @ARGV == 4;
 
open my $ifh1, q|<|, shift or die;
open my $ifh2, q|<|, shift or die;
open my $ofh1, q|>|, shift or die;
open my $ofh2, q|>|, shift or die;
 
while ( <$ifh1> ) {
        chomp;
        $hash{ $_ } = 1;
}
 
while ( <$ifh2> ) {
        chomp;
        if ( exists $hash{ $_ } ) {
                delete $hash{ $_ };
                next;
        }
 
        printf $ofh2 qq|%d\n|, $_;
}
 
for ( sort { $a <=> $b } keys %hash ) {
        printf $ofh1 qq|%d\n|, $_;
}
$ perl script.pl inputfile1 inputfile2 outputfile1 outputfile2
$ cat outputfile1
1233
4444
7777
$ cat outputfile2
1244
9898
9999