#!/usr/bin/perl -wT
use strict;
use utf8;
sub pass_env {
	my (@pass1) = split("&", $_[0]);
	my ($pass2) = join("=", @pass1);
	my (%pass3) = split("=", $pass2);
	return %pass3;
}
sub check_mail {
        #use Email::Valid instead
	if ( (my @valid = split("@", $_[0]) )== 2 ) {
		#continue with regex later...
                return 1;
	}
	else {
		return 0;
	}
}
sub check_vars {
        #use htmlspecialchars() based check
	foreach (@_) {
		if  ( /[><;():]+/ ) {
			return 0;
		}
	}
	return 1;
}
##
my $str = "sub=hello&mail=sometext&text=beeee mooo "; # $ENV{'QUERY_STRING} simulation
my %hash = &pass_env($str);


if ( &check_vars($hash{'sub'}, $hash{'mail'}, $hash{'text'})) { 
	if ( &check_mail($hash{'mail'}) ) {
	print $hash{'sub'},"\n";
	print $hash{'mail'}, "\n";
	print $hash{'text'}, "\n";
	}
	else {
		print "Invalid email.\n";
	}
}
else {
	print "Please, fill all forms.\n";
}