Re (tilly) 3: overloading the print function (or alternatives)

[tilly]

Then you would mess up someone who had inserted:

  print STDERR "Called node 'foo'\n";

as a debugging aid. (The messsage should show up in your webserver's logs.) The following (untested) code is much nicer:

package noprint;
use Carp;

sub PRINT {
  my $msg = Carp::longmess("You must return rather than print");
  print "Content-type: text/plain\n\n$msg";
  die $msg;
}

*PRINTF = *PRINT;

sub TIEHANDLE {
  return bless ({}, shift);
}

and elsewhere in the code:

tie(*NOPRINT, 'noprint');
select(NOPRINT);
# time passes while the page is built.
# Before spitting out the final page:
select(STDOUT);

That catches the newbie error. Without the potential for headaches that overriding print causes.