I think the most efficient solution would be to open the file in read/write mode, then seek to the position where you want to put "test", then write it.

This should not be hard because your lines are of constant length, so you can easily compute the byte position of your target string. However you should take care on certain operating systems that treat "\n" as more than one character.

Tie::File still has to search for the newlines, and (afaik) it operates on whole lines; as I understand it, your lines are much longer than your columns, so this is still very unefficient.

In reply to Re: Question regarding Tie::File or a better way to handle huge 2-D arrays by betterworld
in thread Question regarding Tie::File or a better way to handle huge 2-D arrays by Benbo

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.