Select Code to Download

@filetoread = <INFILE>;            # read in file all at once
my $linestooutput = '';            # place to save output until the en
+d
...
$linestooutput .= join("\t",(split /\s+/)[@ColumnNumbers])."\n" foreac
+h (@filetoread); 
print OUTFILE $linestooutput;

while(<INFILE>)
{
...
    my $outline .= @Line[$col]."\t" foreach my $col (@ColumnNumbers);
    print OUTFILE $outline,"\n";
}