if ($line =~ /\d\d\/\d\d\/\d\d\d\d \d\d:\d\d:\d\d.\d\d\d/) {
$line =~ s#^(\d\d/\d\d/\d\d\d\d \d\d:\d\d:\d\d\.\d\d\d$#$1#;
}

##</code><code>##

perl -le '$cat = "cat"; if ($cat =~ /\143\x61\x74/) { print "Its a cat!\n"; } else { print "Thats a dog\n"; }'