G'day baxy77bax,

Without knowing the (average) record size, it's a little hard to estimate whether this solution fits the 100MB memory limit. If the records are of a similar size to your dummy data, then it probably won't meet that requirement; if they are in the order of hundreds bytes each, then you may be in with a chance.

Anyway, here's the potential solution [Updated - see below]: 

$ perl -Mstrict -Mwarnings -Mautodie -le '
    use Tie::File;

    tie my @input_records, "Tie::File", "./pm_1054101_input.txt";

    open my $out_fh, ">", "./pm_1054101_output.txt";

    print $out_fh $input_records[$_] for
        map { $_->[0] }
        sort { $a->[1] <=> $b->[1] || $a->[2] <=> $b->[2] }
        map { [ $_, map { substr $_, 3 } (split " ", $input_records[$_
+])[0,1] ] }
        0 .. $#input_records;

    close $out_fh;

    untie @input_records;
'

[download]

Input file:

$ cat pm_1054101_input.txt
key1  key2  ndnjfgdsjfjjkjjfjf...
key1  key2  kdfkjdfgdfugbjndkfgkjgndkjfjkd
key43 key21 sdkjfhdghdbgbd
key1  key3  jujdejnsduhffnjj
key2  key2  jhzezhdjjf...

[download]

Output file:

$ cat pm_1054101_output.txt
key1  key2  ndnjfgdsjfjjkjjfjf...
key1  key2  kdfkjdfgdfugbjndkfgkjgndkjfjkd
key1  key3  jujdejnsduhffnjj
key2  key2  jhzezhdjjf...
key43 key21 sdkjfhdghdbgbd

[download]

File sizes unchanged:

$ ls -l pm_1054101_*
-rw-r--r--  1 ken  staff  159 14 Sep 22:41 pm_1054101_input.txt
-rw-r--r--  1 ken  staff  159 14 Sep 23:04 pm_1054101_output.txt

[download]

Update: I removed an intermediary array which might save some memory. Here's the original code:

<Reveal this spoiler or all in this thread>

-- Ken

In reply to Re: sorting type question- space problems by kcott
in thread sorting type question- space problems by baxy77bax

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.