use strict;     # always 'use strict'
use warnings;   # always 'use warnings' or the -w switch

chomp (my @a = <DATA>);    # chomp the array to get rid of extra \n's
my $file = "bas.txt";

# get the open() out of the loop so it's not repeated unnecessarily
open (FILE, ">>$file") || die "Can't open $file: $! \n";

print FILE "$_\n" for @a;  # shorter; sweeter
        
close(FILE);
close(DATA);

__DATA__
222.222.333.444:firstServer
121.222.222.222:secondServer
[download]

I know that I'm not answering your question (it's been done), but those are a few other things to keep in mind for the future.

Zenon Zabinski | zdog | zdog@perlmonk.org