Well, since there is no "s" modifier on the regex, it is at least testing making sure that the value of $command_str does not contain "\n", which might be worth something, depending on how this variable is used later on.

But if the whole script were in my hands, the next thing I would do would be to search for occurrences/uses of $command_str outside (following) that if block, because any such occurrence/usage could be getting a still-tainted value (in the case where that "if" condition wasn't met).

(Update: and then, of course, I would also look very carefully at how this variable is being used inside that "if" block.)

In reply to Re: Taint checking? by graff
in thread Taint checking? by citromatik

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.