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/*	$Id$ */

/*
 * Copyright (c) 2006 Dimitri A. Sokolyuk <demon@dim13.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <assert.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "query.h"

char *
decode(const char *s)
{
	char	*buf, *t;

	assert(s);
	buf = malloc(sizeof(char) * strlen(s) + 1);
	assert(buf);

	for (t = buf; *s != '\0'; ++t, ++s) {
		if (*s == '%') {
			*t  = *++s;
			*t -= isdigit(*s) ? '0' : ((isupper(*s) ? 'A' : 'a') - 0x0a);
			*t *= 0x10;
			*t += *++s;
			*t -= isdigit(*s) ? '0' : ((isupper(*s) ? 'A' : 'a') - 0x0a);
		} else if (*s == '+')
			*t = ' ';
		else
			*t = *s;
	}
	*t = '\0';

	return buf;
}

char *
getquery(char *var)
{
	const	char *qstr;
	char	*buf, *s, *p;

	assert(var);
	qstr = getenv("QUERY_STRING");
	if (!qstr)
		return NULL;
	buf = decode(qstr);

	for (s = buf; *s != '\0'; s = p + 1) {
		for (p = s; *p && *p != '&'; ++p)
			;
		*p = '\0';
		if (strncmp(s, var, strlen(var)) == 0) {
			s = strchr(s, '=') + 1;
			if (strlen(s) == 0)
				break;	/* XXX */
			p = strdup(s);
			free(buf);
			return p;
		}
	}

	free(buf);
	return NULL;
}