There's probably more than one way to accomplish the goal in the title -- and I'd love to hear stories about it, if only because it'd make me feel better.

I had the following, very simple line of code: 

$user = ~ s/^\s+|\s+$//gs;

[download]

The intention, of course, was to trim white space from the beginning and end of a user name previously parsed from a record. Instead, though, $user ended up containing a large and random-seeming number.

Spot the bug?

<Reveal this spoiler or all in this thread>

Stepping through the code with the debugger found the line where the oddness was occurring, but it seemed like inexplicable madness (for something like 10 minutes) until I noticed that one extra space. Man, do I feel stupid!

The lesson? I probably should have used Text::Trim. :)

<–radiant.matrix–>
Ramblings and references
The Code that can be seen is not the true Code
I haven't found a problem yet that can't be solved by a well-placed trebuchet

In reply to How to introduce a frustrating bug with a single whitespace by radiantmatrix

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.