use of uninitialised value

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: use of uninitialised value by Joost (Canon) on Mar 07, 2005 at 18:32 UTC
If the warning is from the open() line, either $upload_dir or $filename is undefined. If you want more info on warnings and errors, try doing `use diagnostics;` [download] at the top of your program, or look them up at the perldiag manual page. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]
Re: use of uninitialised value by friedo (Prior) on Mar 07, 2005 at 18:32 UTC
Perl optimizes things like `"$upload_dir/$filename"` to `$upload_dir . '/' . $filename`, which is why the warning is complaining about the concatenation operator. One of those variables is not initialized. Try printing them to see which one it is. You've probably got a typo somewhere. If one of them is supposed to be empty in some circumstances, make sure it's set to the empty string ("") instead of remaining uninitialized.	[reply]
Re: use of uninitialised value by sh1tn (Priest) on Mar 07, 2005 at 19:08 UTC
IMHO you should check "what's behind" - `-d $upload_dir or die "$upload_dir: $!"; -f $filename or die "$filename: $!"; # if we are here - we have valid directory and file open (UPLOADFILE,"<$upload_dir/$filename") or die $!;` [download]	[reply] [d/l]
Re^2: use of uninitialised value by ysth (Canon) on Mar 07, 2005 at 23:46 UTC
That would need to be: `-d $upload_dir or die "$upload_dir: $!"; -f "$upload_dir/$filename" or die "$upload_dir/$filename: $!";` [download]	[reply] [d/l]
Re^3: use of uninitialised value by sh1tn (Priest) on Mar 08, 2005 at 07:38 UTC
Thank you. My error comes from the lack of fully written sample: `my $filename = "$upload_dir/$filename"; -d $upload_dir or die "$upload_dir: $!"; -f $filename or die "$filename: $!"; # I'm not in the secret why those endless absolute # filepaths are scattered almost always` [download]	[reply] [d/l]
Re: use of uninitialised value by hok_si_la (Curate) on Mar 07, 2005 at 18:36 UTC
Greetings, My guess is that you are getting that warning from not declaring a scalar that is being used. Perhaps you did not declare $upload or $filename. This would explain both the warning, and the problem opening the file. hok_si_la	[reply]