It turns out that $mode is what is undefined. Perl is reporting the wrong line number because it has optimized the entire if/elsif/else into a "case" (or "switch") statement.

Update: Well, the case/switch statement bit may or may not enter into it. I recall old documentation talking about simple if/elsif/else being internally optimized into a case/switch type of flow control. What I have been able to verify is that Perl is not recording line number of the elsif lines. One easy way to see this is: 

perl -d script.pl
  DB<2> l 32-46
32:       if($line =~ m/<!-- LHS movie -->/) {
33:         $mode ="LHS";
34:         $moviecounter++;
35:         $internal=0;
36        } elsif ($line =~ m/<!-- RHS movie -->/) {
37:         $mode = "RHS";
38:         $moviecounter++;
39:         $internal=0;
40        } elsif ($line =~ m/<!-- theater -->/) {
41:         $mode = "theater";
42:         $counter++;
43:         $moviecounter=-1;
44:         $internal=0;
45        } elsif ($mode eq "LHS") {
46:         if ($internal == 6 ) {

[download]
and notice that the elsif lines don't have colons (":") after their line numbers. This is probably worth bringing to the attention of p5p to see if it can be fixed.

        - tye (but my friends call me "Tye")

In reply to (tye)Re: uninitialized weirdness by tye
in thread uninitialized weirdness by vaevictus

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