Your "1st" try seems to be discussed here. Do a Super Search on "sliding window". This is the approach you're using in the OPed code, although the size of the window you're using is microscopic; it will work a lot better with a 100 MB - 1GB window, assuming 4GB system RAM.

The simplest approach is to do a regex search on the the entire file slurped into system memory, but this does not scale well for large files, "large" being in the range you mention, although this depends on your hardware; it would be a trivial approach on a system with, say, 8GB of system RAM.

Give a man a fish:  <%-{-{-{-<

In reply to Re: File extraction 2nd try by AnomalousMonk
in thread File extraction 2nd try by knight.of.ni

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.