For that specific task, I'd probably use index rather than a regex. 

if (index($filename, $account) >= 0) {
    print $filename."\n";
}
else {
    print "No match for $account\n";
}

[download]

One consideration may be where $account appears in $filename.

You can Benchmark if speed is important.

By the way, the code you posted doesn't compile: you possibly meant \b instead of /b (which gives the syntax error: Unknown regexp modifier "/b" ...); however, fixing that gives: No match for 7766541.

-- Ken

In reply to Re: Search for account number in a file name by kcott
in thread Search for account number in a file name 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.