Wow. Reading the replies made me wonder what exactly you were after. If it is to list (alphabetically) the data and the sum for each, it seems BrowserUK had what I got (without the final sort). If that is the solution you want, this code does what BrowserUK's does and in additon, sorts the final output. 
#!/usr/bin/perl
use strict;
use warnings;
use 5.014;

my %data;
while (<DATA>) {
    chomp;
    my ($v, $k) = split /,/;
    $data{ $k } += $v;
}

print "$data{$_},$_\n" for sort keys %data;

__DATA__
1208782,abc
406744,def
367455,abc
283191,mps
226159,abc
197688,rxwz
137875,rxwz
115901,abc
107297,def
99213,mps

[download]

And the result is: 

1918297,abc
514041,def
382404,mps
335563,rxwz

[download]
Chris

In reply to Re: Alphanumeric sort by Cristoforo
in thread Alphanumeric sort by zac_carl

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.