9 characters long? Does 1.3456789 count? Or do you really mean 5 digits after the decimal place only? I'm assuming the latter. And that the - sign doesn't count. 

  /^-?(\d{1,3}(?:\.\d{1,5})?)$/

[download]
That is, an optional leading - sign, followed by 1 to 3 digits (to allow for 180 degrees East/West), followed, optionally, by a dot, and then 1 to 5 more digits.

Better yet, try: 

  use Regexp::Common;
  /^$RE{num}{decimal}{-places=>'0,5'}$/ and $_ <= 180;

[download]
No sense reinventing the wheel. :-)

In reply to Re^3: Filtering CGI Input by Tanktalus
in thread Filtering CGI Input by awohld

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.