The following code should do what you want. Essentially, it's a finite state machine.

Hope this helps, -gjb-

use strict; use warnings; my $currentPos; my $processing = 0; while (<DATA>) { chomp($_); if ($_ eq q(START OF RECORD)) { $currentPos = tell(DATA); } elsif (/INFORMATION I AM LOOKING FOR/ && !$processing) { seek(DATA, $currentPos, 0); $processing = 1; } elsif ($_ eq q(END OF RECORD)) { $processing = 0; } elsif ($processing) { print "$_\n"; } } __DATA__ START OF RECORD LINE 1 INFORMATION I AM NOT LOOKING FOR LINE 3 LINE 4 LINE 5 LINE 6 END OF RECORD START OF RECORD LINE 1 ok INFORMATION I AM LOOKING FOR LINE 3 ok LINE 4 ok LINE 5 ok LINE 6 ok END OF RECORD START OF RECORD LINE 1 LINE 2 LINE 3 LINE 4 INFORMATION I AM NOT LOOKING FOR LINE 6 END OF RECORD START OF RECORD LINE 1 ok LINE 2 ok LINE 3 ok LINE 4 ok INFORMATION I AM LOOKING FOR LINE 6 ok END OF RECORD

In reply to Re: Read forward and backward - need help by gjb
in thread Read forward and backward - need help by Limbic~Region

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.