I forgot the email account should be case insensitive. perl -ne 's/\s//g; s/@.*$//; $h{lc $_}++; END { print $_, "\n" for sort keys %h}' -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.pm.org/pipermail/china-pm/attachments/20071026/3028cb4d/attachment.html