Look for sigils. Any place (in the string) where there's a $ or @, for instance, Perl will attempt to interpolate the corresponding variable.

When I run it at the command line, I get this:

Content-Type: text/html; charset=ISO-8859-1

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html
    PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-U
+S"><head><title>
</title>
[Fri Apr 29 07:36:15 2005] temp.pl: Use of uninitialized value in stri
+ng eq at temp.pl line 36.
[Fri Apr 29 07:36:15 2005] temp.pl: Use of uninitialized value in stri
+ng eq at temp.pl line 36.
[Fri Apr 29 07:36:15 2005] temp.pl: Use of uninitialized value in stri
+ng eq at temp.pl line 36.
[Fri Apr 29 07:36:15 2005] temp.pl: Use of uninitialized value in conc
+atenation (.) or string at temp.pl line 54.
</head><body><p>Logic error, unknown choice: </p>/root #

[download]

In this case, it appears to be $choice and $payment that are undefined, causing these warnings. However, the one you are getting comes from a different place in the code, and so it may be a different variable.

If you can't figure out where it is by looking at the code, I know two tricks to narrow it down:

  1. Use Data::Dumper to show you what your various variables really are; look for ones that are undef and should be defined.
  2. Failing that, split up your big long string into pieces. Start by splitting it in half, then when you run again the line number will tell you which half is the problem; split that half in half again, and repeat until you've got a string with just one interpolation in it; there is your problem.
"In adjectives, with the addition of inflectional endings, a changeable long vowel (Qamets or Tsere) in an open, propretonic syllable will reduce to Vocal Shewa. This type of change occurs when the open, pretonic syllable of the masculine singular adjective becomes propretonic with the addition of inflectional endings."  — Pratico & Van Pelt, BBHG, p68

In reply to Re: Do not undertand this error message by jonadab
in thread Do not undertand this error message by b310

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