If you want just know there was a change, go with File::Compare mentioned above.

I think you probably need to know what files were added and removed, in other word difference between your file list. You can try following approach:

First make sure your lists in files are sorted. Then use Text::Diff module like this:

use Text::Diff;

my $diff = diff "saved_system.txt", "current_system.txt", { STYLE => "
+OldStyle" };

my (@added,@removed);
for(split /\n/,$diff) {
    next if /^\d/;     # skip line numbers
    push @added,$1   if /^> (.*)$/;
    push @removed,$1 if /^< (.*)$/;
}

print "Added files:\n";
for my $file (@added) {
    print $file,"\n";
}

print "\nRemoved files:\n";
for my $file (@removed) {
    print $file,"\n";
}
[download]

It prints output to console, but it is easy to change for printing into file.

-- hope this helps, Roman