Check Timemachine Output for "0 bytes/sec" and insert error warning into stream/pipe

warningcheck.pl

#!/usr/bin/env perl

use strict;
use warnings;

my $special_string = "0 bytes/sec";

sub process_text_pipe {
    my @output;
    while (<>) {
        my $line = $_;
        chomp $line;
        if ($line =~ /$special_string/) {
            $line .= "\n\n !!!! ERROR ERROR ERROR ERROR !!!!\n";
        }
        push @output, $line;
    }
    return @output;
}

my @processed_output = process_text_pipe();

foreach my $line (@processed_output) {
    print "$line\n";
}