May  2 07:06:20 lon.mail.net exim[1234]: 2012-05-02 07:06:20 1PSPtU-0004en-1e <= it_ndt_bounces@new.itunes.com H=smtpmail.com [21.5.10.4] I=[8.4.14.4]:25 P=esmtp S=1966 id=1603882764.112965659.1335927964793.Mail.cboxp@ednabay.apple.com T="New on iTunes: One Thing And, Then Another, Cooking Apps,\n Great Deals on First Seasons, and M"
May  2 07:06:20 lon.mail.net exim[1234]: 2012-05-02 07:06:20 1PSPtU-0004en-1e <= it_ndt_bounces@new.itunes.com H=smtpmail.com [21.5.10.4] I=[8.4.14.4]:25 P=esmtp S=1966 id=1603882764.112965659.1335927964793.Mail.cboxp@ednabay.apple.com T="New on iTunes: One Thing And, Then Another, Cooking Apps,\n Great Deals on First Seasons, and M"
May  2 07:06:20 lon.mail.net exim[1235]: 2012-05-02 07:06:20 1PSPtU-0004en-1e => peterpiper <peterpiper@nosuchdomain.net> R=local_mail T=local_maildir_mail_drop
##</code><code>##

#!/usr/bin/perl
use strict;
use warnings;
no warnings q{uninitialized};

while (my $line = <STDIN>) {
chomp($line);
my ( $mon, $day, $time, $loghost, $prog, $remainder ) =
   split m{:?\s+}, $line, 6;
my %monthNos = do {
   my $no = 0;
   map { $_ => ++ $no }
   qw{ Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec };
   };
my ( $user ) = 
    $remainder =~ m{user=([^,]+)};
my ( $rip ) = $remainder =~ m{rip=([^,]+)};
$remainder =~ tr/"/'/;
my $yr = q{2012};
my $csv = sprintf q{%02d/%02d/%s %s,%s,%s,"%s",%s,%s},
   $day, $monthNos{ $mon }, $yr, $time, $loghost, $prog, $remainder, $user, $rip;

print "$csv\n";
}

##</code><code>##

if contains <= then ......
else if contains => then .....
else if contains == then ....
else if contains ** then ....
else somethingelse
etc