#!/usr/bin/perl -w
use strict;

$date = `date +"%l:%M:%S"`; # I'd use sprintf and localtime
my %service= (
    www => qr/:0050\s/,
    ssh => qr/:0016\s/,
    irc => qr/:1A0B\s/,
    ftp => qr/:0015\s/,
);
my %count= qw( www 0 ssh 0 irc 0 ftp 0 );
foreach my $line (  grep /\b01\s/, `cat /proc/net/tcp`  ) {
    foreach my $svc (  keys %service  ) {
        $count{$svc}++   if  $line =~ $service{$svc};
    }
}
open (FILE, "+>/var/www/web/main.txt")
  or  die "Can't write to /var/www/web/main.txt: $!\n";
print FILE "There are $count{www} web, $count{ftp} ftp, ",
  "$count{ssh} ssh, and $count{irc} irc connections ",
  "to this server as of $date\n";
close FILE;