GAH! Stop right now. Go get CGI and use it. I really mean it, you really should not be using code like what you are doing. Nothing we say about your particular issue will be as important as using the CGI.pm module. Do that first, then come back and ask again.

update to give an example

#!perl -w
use strict;
use CGI qw(:all);
my $FORM = param->Vars;
my $textarea = $FORM{"text_area_field_name"};
my @numbers = split /\s+/, $textarea.
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(When I said "go get CGI.pm" I was speaking metaphorically, you don't actually need to "get" anything, it comes with perl.