Want to sort the second column with reference/dereference

AA 34

AB 22

AC 12 

#!/usr/bin/perl -w
print "Please enter the file name: \n";
$file =<STDIN>;
chomp $file;
unless(open(FILE, $file))
{
print "error opening file $file! \n";
exit;
}
@f=<FILE>;
close FILE;
$outputfile="sorted_ABA_2.5_nw";
unless(open(ABA, ">$outputfile"))
{
print "error opening file $outputfile \n";
exit;
}
foreach $line (@f)
{
@AB=split("\t", $line);
#print "@AB";
#print "$AB[1]", "\t";
#print "$AB[2]";
@AA = sort{$a->[1] <=> $b->[1]} @AB;
foreach $temp (@AA)
{
print "@$temp\t", "\n";
}
}
close ABA;

[download]

The program is not running and output shows the use of uninitalized value <=>.. Any solution..

In reply to sorting first column by vis1982

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