How about this?

use strict;
use warnings;
use File::Copy;
use Tie::File;

copy( $ARGV[0], $ARGV[1] ) or die $!;
my @file;
tie @file, 'Tie::File', $ARGV[1] or die $!;
@file = sort @file;
untie @file;

[download]

Tie::File has low memory requirements: The file's lines are treated as a disk-based array. File::Copy concisely copies the source file to a target filename. Then we tie the target file and sort it.

I can't vouch for it being particularly fast; I suspect the OS version of sort is better optimized for disk-based sorting.

Update: Ooh I hate when first instinct is misguided. Well, second instinct really, first instinct is to use the tools that are already written and proven (ie, the Linux sort utility). This muse fails as MidLife pointed out: The sort itself isn't done 'inline', and thus the memory usage will soar. And of course not even Evel Knievel could jump the valley separating the speed of the established tool versus this hack. :)


Dave

In reply to Re: Sort command equivalent in perl by davido
in thread Sort command equivalent in perl by sandeepau

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.