If you had an array of file names, and did the following:
    my @grepped = grep /\d{8}\.txt$/ @filenames;

[download]
..then your array @grepped would contain the entry 'file1_system_051117123050.txt' if this filename was in the @filenames array.

However, if you want to capture text from a string, then you want a regular expression match:

    if ( $filename =~ m/(\d{4})\d{4}.txt$/ ) {
        print( $1 . "\n" );
    }

[download]
..if $filename contained 'file1_system_051117123050.txt' then you would have '1712' printed out as that was the four digits captured within parenthesis (curly brackets) in the regular expression match.

In reply to Re: grep question by monarch
in thread grep question by darrengan

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.