(jcwren) RE: Easy, elemental, but cool debug trick.

[jcwren]

I use a similiar technique. When debugging a CGI application, however, prints can really mess you up.

For that situation, I have a routine (below) that writes to a file. It accepts two parameters, one which is a class string, and a message string. The section string allows me to put messages in a arbitrary category (say, 'debug', 'authentication', or 'SQL'), and the text to be printed.

Each message is timestamped, and also stamped with a user ID (that's internal to me application, and could be ignored).

I also have a similiar version that use the syslog facility to write /var/log/messages.

sub debug_log
{
   @_ == 2 or confess "Incorrect number of arguments";

   my ($section, $action) = @_;
   my $userid = 0;
   my $string = 0;

   $userid = $globalUserID || "<nobody>";

   $string = sprintf ("%s %s %s:%s\n", scalar localtime, $userid, $sec
+tion, $action);

   open (SINK, ">> /home/httpd/somedir/logfile") or confess "Can't ope
+n logfile";
   print SINK $string;
   close (SINK) or confess "Can't close logfile";
}

[ask]

Just always use warn "foobar" if $DEBUG instead of print, then it will do the right thingtm under both mod_cgi and mod_perl. For logging you should take a look at the Log::Agent module available on CPAN.