Here's a way to do it using split within a Schwartzian Transform:

#!/usr/bin/perl

use strict;
use warnings;

my @data = <DATA>;

# Schwartzian Transform
print map  { $_->[0] }
      sort { $a->[1][1] <=> $b->[1][1] or $a->[1][0] <=> $b->[1][0] }
      map  { [ $_, [ (split m/,/, $_, 3)[0, 1] ] ] }
      @data;

__DATA__
1,64,1.4.5,1.4.6,44642850,44642850,0,27348,10028,59188,1488095,761904.
+64
1,128,1.4.5,1.4.6,25337850,25337850,0,19236,10276,28196,844595,864865.
+28
1,256,1.4.5,1.4.6,13489200,13489200,0,17792,11372,17832,449640,920862.
+72
1,512,1.4.5,1.4.6,6996270,6996270,0,18084,16744,19124,233209,955224.06
+4
1,1024,1.4.5,1.4.6,3557880,3557880,0,31528,20488,35188,118596,971538.4
+32
2,64,1.4.5,1.4.6,44642850,44642850,0,25828,9548,40128,1488095,761904.6
+4
2,128,1.4.5,1.4.6,25337850,25337850,0,27936,10796,28696,844595,864865.
+28
2,256,1.4.5,1.4.6,13489200,13489200,0,12852,10692,13332,449640,920862.
+72
2,512,1.4.5,1.4.6,6996270,6996270,0,17184,15904,18844,233209,955224.06
+4
2,1024,1.4.5,1.4.6,3557880,3557880,0,34068,17948,36628,118596,971538.4
+32

[download]

UPDATE: If you prefer regular expression pattern matching to split-ting in this case, just replace the initial map with this:

      map  { [ $_, [ m/^(\d+),(\d+)/ ] ] }

[download]

In reply to Re: numeric sort on substring by Jim
in thread numeric sort on substring by Anonymous Monk

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