On Wed, May 26, 2010 at 1:06 PM, HACKER Nora <nora.hac...@stgkk.at> wrote:
> Hi,
>
> I am having troubles with a variable that should not be defined but
> seems to be somehow. In the following code, the variable $localdir is
> declared, then I am doing a find, and in case I get a result the
> returned path is assigned as a value to $localdir. But somehow the
> latter IF results to TRUE (=$localdir is defined) although the find does
> not return a path (which is ok for my current test). Please could tell
> me what I do not understand? I thought this was the proper way to check
> whether a variable has a value or not (or at least my Perl book says
> so)!?
>
> *** snip ***
>
> my $localdir;
> if (defined $localdir) { print "defined 1: $localdir\n"; } #
> undefined = ok for this test
>
> my $find = File::Finder->type('d')->name("$sdir")->print;
> $localdir = find ( $find, "$dbpath/dumps");
> if (defined $localdir) { print "defined 2: $localdir\n"; } #
> DEFINED although no directory :-(
>
> *** snip ***
>
> Kind regards,
> Nora
>
> Hi Nora,
Ok, so what is in $localdir when it is printed? I suspect that the answer is
an empty string. If so then Perl is 100% correct as most likely File::Finder
will return the result of it's findings in a string format thus if it finds
nothing it returns a empty string. Which means $localdir is actually
defined.
Try adding the following to the if ( defined ... ) statement: if ( defined
$localdir && $localdir ne q{} ) { print ... } # q{} is the same as '' or ""
but it is more readable in many font types.
Regards,
Rob
