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#!/usr/bin/perl -w

use strict;
use CGI;

my $cgi = new CGI;

my $email = $cgi->param('unsubscribe');

print $cgi->header();
print $cgi->start_html(-title=>"unsubscribe");


if ( $email eq "" ) {
	print $cgi->startform(-action => 'unsubscribe.pl', -method => 'POST');
	print "unsubscribe: ".$cgi->textfield(-name=>'unsubscribe',-size=>'50',-maxlength=>'50');
	print $cgi->submit("send").$cgi->reset("reset");
}
else {
	my ($name, $domain) = split(/@/, $email);
	
	if ( $name eq "" || $domain eq "") {
		print "name or domain is empty";
	}
	elsif ( $name =~ /\W/ && ! $name =~ /[\.-_]/ ) {
		print "name contains illegal charakters!";
	}
	elsif ( $domain =~ /\W/ && ! $domain =~ /[\.-_]/ ) {
		print "name contains illegal charakters!";
	}
	elsif ( length($name) < 3 || length($domain) < 6 ) {
		print "This email address is too short";	
	}
	elsif ( ! $domain =~ /[\w\.-_]+\.[\D\D]+/ ) {
		print "invalid domain";
	}
	else {
		print "unsubsribing: $email";
		
		open (FILE,  "./unsubscribe.txt") or die "cannot create/open unsubscribe.txt!";
		prinf FILE $email."\n";
		close FILE;
	}
}


print $cgi->end_html();