Your regular expression does match because it is really present inside the string:
"[someRandomName]." (The text in bracket is the matched text)
"[someRandomName]-"

What you want is anchoring the regular expression. Try adding a '^' at the beginning and a '$' at the end of the regular expression. The Regex will then try to match against the whole string, and not only on a part of it:

/^[A-Z0-9]+[A-Z0-9-]+[A-Z0-9]{1}$/i

Hope this helps. See perlre for more infos about this

#!/usr/bin/perl -w
use strict;
my $domain = $ARGV[0];
print "Got $domain\n";
if ($domain =~ /^[A-Z0-9]+[A-Z0-9-]+[A-Z0-9]$/i)
{
        print "$domain matched\n\n";
}
else
{
        print "$domain did not match\n\n";
}
__END__
Got someRandomName.
someRandomName. did not match

Got someRandomName-
someRandomName- did not match

Got someRandomName
someRandomName matched

Got someRandomName-X
someRandomName-X matched

Got someRandomName-Foo
someRandomName-Foo matched

[download]
<kbd>--
my $OeufMayo = new PerlMonger::Paris({http => 'paris.mongueurs.net'});</kbd>

In reply to Re: Regular expression matching when it shouldn't by OeufMayo
in thread Regular expression matching when it shouldn't by Anonymous Monk

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.