Monks,

I am iterating over a group of log files which has, in total, a few million lines easily. I am doing this with a while loop going line by line. Every so often, I come across a line that isn't getting parsed correctly and thus not correctly inserted into my hash and thus throws a "Use of uninitialized value in concatenation ..." warning. (I am using this to find the "exceptions" in the log file). I catch that warning, and print out the variables associated with it. So far so good, but I recreate the signal catcher every iteration (every line) otherwise I get an error of undefined variables: 

while (my $line = <LOG>) {
 my (@entry) = split(/\s+/, $line);
 my (@edate) = Parse_Date(substr($entry[0],0,10));
 my ($http_code) = substr($entry[3], -3);
 my ($url) = "$1$2"
      if ($entry[6] =~ m|^http://.*v1=(.*)&v2=(.*)&v3=.*$|);

 $SIG{'__WARN__'} = sub {
   print "WARNING: ". $_[0] ."\n".
         " http_code: $http_code\n".
         " url: $url\n".
         " edate[0]: $edate[0]\n".
         " edate[1]: $edate[1]\n".
         " edate[2]: $edate[2]\n".
         " edate[3]: $edate[3]\n"
     if ($_[0] =~ /^Use of uninitialized value in hash element.*$/);
 };

 $STATUS{$http_code}{$url}{$edate[0]}{$edate[1]}{$edate[2]}{$edate[3]}
+++;
}

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Optimally, I would like to only run that warning handler once at the beginning of the script, but since those variable are locally scoped and recreated every iteration (i'm sure there is a better way to do that too that I am not aware of), I have to setup the handler after all the variables have been delcared. Can someone tell me the best way to handle this or if this is good enough?

In reply to Catching Warnings and Showing Uninitialized Variables by madbombX

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