#!perl
use strict; # Always.

my $useage = "perl script.pl column# file1 file2 etc.\n";

my $column  = shift @ARGV or die $useage;
--$column; # zero base instead of one base.

my @input;
push( @input, [ split /,/ ] ) while(<>);
@input = sort {$$a[$column] cmp $$b[$column]} @input;

print join( ', ', @$_ ), "\n" for @input;
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