Simple print-and-log subroutine

I find that I have a use for this almost all the time. It's a silly little set of subs, but in my role as sysadm, I often need to go back and see what all those printed messages were.

So here is my not-so-elegant workhorse for when I need to stuff things into logs, and shuffling modules isn't an option. I hope it's useful for someone else, too.

Dependencies, assumptions and prerequisites:

• Perl 5-ish
• Pre-defined global variables:
  • $level - log level (undef = normal, 1 = warn, 2 = die)
  • $logfile - a logfile that we can append to
  • $msgprefix - a program or subroutine specific prefix
  • $verbose - whether to print to STDOUT
• Preferably disabled output buffering

Usage:

&plog("Log this");
&plogwarn("Warn about and log this");
&plogdie("Log this and die");

The code:

sub plogwarn
{
   my $msg = shift;
   &plog ($msg,1);
}

sub plogdie
{
   my $msg = shift;
   &plog ($msg,2);
   exit 1;
}

sub plog
{
   my $msg = shift;
   my $level = shift;
   my @lt = localtime;
   # Format current datetime sensibly:
   my $dt = sprintf("%d-%02d-%02d %02d:%02d:%02d",
                    $lt[5]+1900,$lt[4]+1,
                    $lt[3],$lt[2],$lt[1],$lt[0]);
   warn "$dt $0: sub plog: No message!\n" unless defined $msg;
   unless (open(F,">>$logfile")) {
       warn "$dt $0: sub plog: Failed to open logfile ($logfile) for write.\n";
   } else {
       print F "$dt $msgprefix$msg\n";
       close F;
   }
   if ($verbose) {
       unless (defined($level)) {
           print "$dt $msgprefix$msg\n";
       } elsif ($level == 1) {
           warn "$dt $msgprefix$msg\n";
       } elsif ($level == 2) {
           die "$dt $msgprefix$msg\n";
       }
   }
}