# cgi.pl - decode CGI input.
#
# Usage:
#	require 'cgi.pl';
#	&cgi'decode;
#	...
#	$name = $cgi'tags{'name'};

package cgi;

sub header {print "Content-type: text/html\n\n";}

sub decode {
	local($args, $n_read, *terms, $tag, $value);

	$ENV{'REQUEST_METHOD'} eq "POST" ?
	($n_read = sysread(STDIN, $args, $ENV{'CONTENT_LENGTH'})):
	($args = $ENV{'QUERY_STRING'});

	@terms = split('&', $args);

	foreach (@terms) {
		($tag, $value) = split(/=/, $_, 2);
		$value =~ s/\+/ /g;
		$value =~ s/%([0-9A-Fa-f][0-9A-Fa-f])/pack("c", hex($1))/ge;
		$tags{$tag} = $value;		# tags is global
	}
}

sub pack {
	local($value) = @_;
	$value =~ s/(\W)/sprintf("%%%.2X", ord($1))/ge;
	$value =~ s/%20/+/g;
	return $value;
}
1;