/var/log/messages is a file. The default place to go for log messages on Linux and IHMO the best in most cases (still assuming you are on Linux). If you are on Windows the Event Log or what ever they call it in English, is a good place too.

Type file /var/log/messages and you will see /var/log/messages: ASCII English text, with very long lines. Or i hope so ;-) Please see also Sys::Syslog and syslog as well as the hints marto gave below (perhaps you should start there...)

I mentioned already in the CB that you should consider just to print to STDOUT and STDERR and then redirect the stuff to a file (your_prg.pl > your_log.log). By far the easiest solution to begin. See redirections for further information about this. The links marto provided should be helpful for learning how to do so.

EDIT: fixed little typo...

Best regards, Karl