Use of uninitialized value for file name

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

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Re: Use of uninitialized value for file name by wfsp (Abbot) on Apr 13, 2006 at 16:54 UTC
When I'm stumped I often try reducing the script to the bare bones to get something working and gradually add things back in. Something like: `#!/usr/bin/perl use warnings; use strict; my $dir = 'c:/Perl'; opendir DIR_A, $dir or die $!; while(my $job = readdir(DIR_A)){ print "$job\n"; } __DATA__ ---------- Capture Output ---------- > "C:\Perl\bin\perl.exe" _new.pl . .. bin Desktop.ini eg html lib myperl site Tidy > Terminated with exit code 0.` [download] When you come up against the error you'll have a better chance of narrowing down the source of your grief. Hope that helps.	[reply] [d/l]
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Re: Use of uninitialized value for file name by duff (Parson) on Apr 13, 2006 at 16:00 UTC
It says Use of uninitialized value for $job. Are you sure? What is the exact error message? How do you know it's not complaining about `$directory_location`? BTW, there's no need to quote your variables when concatenating them. A simple `$directory_location.$job` will suffice. duff	[reply] [d/l] [select]
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Re: Use of uninitialized value for file name by moklevat (Priest) on Apr 13, 2006 at 15:59 UTC
When `readdir` runs out of entries in the directory it returns an undefined value in scalar context. Update:...but that won't explain why you get an initialization error. For example `#!/usr/bin/perl use warnings; use strict; opendir(DIR_A, './testdir') or die $!; while (my $job = readdir(DIR_A)) { print "$job\n"; if ($job =~ /something/) { print "Something was seen\n"; } }` [download] prints `. ..` [download] when testdir is empty, and prints `. .. something.pl Something was seen` [download] when testdir contains the file something.pl.	[reply] [d/l] [select]
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