AGCT 0 370 1
AGAG 0 32 0
TGAA 2 233 0
AGGT 3 52 1

##</code><code>##


use strict;        # before anything else
use Sort::Fields;  
use Data::Dumper;

open(INP,"data.txt") || die "where's the file eh?";
my @data=<INP>;

chomp (@data); # remove new line characters

print "before sorting...\n";
print Dumper @data;  

#sort the data on the 2nd and the 4th field
#this is numeric sort, as indicated by the "n"

my @sorted = fieldsort '\t', [ '2n', '4n' ], @data;  

print "after sorting...\n";
print Dumper @sorted;


##</code><code>##

before sorting...
$VAR1 = 'AGCT	0	370	1';
$VAR2 = 'AGAG	0	32	0';
$VAR3 = 'TGAA	2	233	0';
$VAR4 = 'AGGT	3	52	1';
after sorting...
$VAR1 = 'AGAG	0	32	0';
$VAR2 = 'AGCT	0	370	1';
$VAR3 = 'TGAA	2	233	0';
$VAR4 = 'AGGT	3	52	1';