trim space, tab, and line break

trim.pl

#!/usr/bin/perl
use strict;
use warnings;

open(FILE, 'index.php') or die "$!";
while (my $line = <FILE>) {
    unless ($line =~ /[^(\s|\t|\n)]/g) {
        $line =~ s/(\s|\t|\n)//g;
    }
    print $line;
}
close(FILE);