> This is a fairly primitive way to do it:

using a sliding window (safer with huge streams)

use strict;
use warnings;
use Data::Dump;

my @window;

push @window, scalar <DATA> for 1..5;                     # init

while (my $line = <DATA>) {
    push @window, $line;
    chomp @window;
    
    if( $window[3] =~ m/[^\d]+\d+/ ){
         dd \@window;
    }

    shift @window;
}



__END__
alpha
beta
something
a07607
b-alpha
b-beta
b-something
b-something else
c-alpha
c-beta
c-somethin
a9706
d-alpha
d-beta
d-something
d-something else

[download]
--> 
["alpha", "beta", "something", "a07607", "b-alpha", "b-beta"]
["c-alpha", "c-beta", "c-somethin", "a9706", "d-alpha", "d-beta"]

[download]

Cheers Rolf

( addicted to the Perl Programming Language)

update

maybe more elegant

use strict;
use warnings;
use Data::Dump;

my @window;

while (my $line = <DATA>) {
    push @window, $line;
    next if @window < 6;                # init
    
    if( $window[3] =~ m/[^\d]+\d+/ ){
        dd \@window;
    }

    shift @window;
}

[download]

Update

Oh the latter (more elegant) approach has a clear advantage, if you want to avoid overlapping results you just need to empty the window after a match and it gets automatically refilled. :)

In reply to Re^2: Grab 3 lines before and 2 after each regex hit (sliding window) by LanX
in thread Grab 3 lines before and 2 after each regex hit by HarryPutnam

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.