my %service = qw(
    0050    www
    0016    ssh
    1A0B    irc
    0015    ftp
);
my $match_lst = join "|", keys %service;
my $match = qr/:($match_lst)\s/;

##</code><code>##

foreach my $line (grep /\b01\s/, `cat /proc/net/tcp`  ) {
    ++$count{$service{$1}} while $line =~ /$match/g;
}