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Displaying symbol tables for debugging

by integral (Hermit)
on Feb 09, 2003 at 08:37 UTC ( #233859=snippet: print w/ replies, xml ) Need Help??

Description: Although there are now Devel:: modules on CPAN which do an excellent job of making symbol tables easy to play with, I wrote these three routines for quick debugging of some code which played around with Safe and other symbol table tricks.
sub packages {
  print "Packages: ", join(" ", grep /::$/, keys %::), "\n";
  print "  INC: ", join(" ", sort keys %INC), "\n";

sub symbols {
  my $pkg = $_[0] || '';
  no strict 'refs';
  print "Symbols: ", join(" ", sort keys %{$pkg.'::'}), "\n";

sub symbols2 {
  my $pkg = $_[0] || '';
  no strict 'refs';
  print "Symbols in ${pkg}::\n";
  my $hash = *{$pkg.'::'}{HASH};
  for (sort grep {!/::$|^_</} keys %$hash) {
    my $sym = $_;
    my $glob = $hash->{$_};
    $sym =~ s/[[:cntrl:]]/'^' . chr(ord($&) + ord('@'))/ge;
    print "  $sym (", *{$glob}{PACKAGE}, '::', *{$glob}{NAME}, "): ";
    if (defined $$_) {
      print "SCALAR='$$glob' ";
    for my $THING (qw(ARRAY HASH CODE IO)) {
      my $ref = *{$glob}{$THING};
      if (defined $ref) {
        print "$THING=$ref ";
    print "\n";
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