I have a script that loops through a directory and it's sub-dir's. To get the files in the directory root I either make the sub-dir undefined or a null string. My question is a style and usage issue as "-w" complains if it's undefined. Is there a better way to do this sort of thing? Here's a quick test script of what I'm talking about: 
#!/usr/local/bin/perl -w

use strict;

my $dir = '/tmp/';
my $sub_dir;
my $file = 'foo.txt';
my $path = "${dir}${sub_dir}${file}";

print "$path\n";

[download]
This causes the "Use of uninitialized value in concatenation" error. But if you set $sub_dir = ""; it halts the warnings. Just looked kind of odd/ugly, thus why you are reading this now.

-THRAK
www.polarlava.com

In reply to Handling uninitialized values by THRAK

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.