strtonum.c revision 1.1 
1/*	$NetBSD: strtonum.c,v 1.1 2015/01/16 18:41:33 christos Exp $	*/
2/*-
3 * Copyright (c) 2014 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Christos Zoulas.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__RCSID("$NetBSD: strtonum.c,v 1.1 2015/01/16 18:41:33 christos Exp $");
33
34#define _OPENBSD_SOURCE
35#include <stdio.h>
36#include <stdlib.h>
37#include <errno.h>
38#include <inttypes.h>
39
40/*
41 * Problems with the strtonum(3) API:
42 *   - will return 0 on failure; 0 might not be in range, so
43 *     that necessitates an error check even if you want to avoid it.
44 *   - does not differentiate 'illegal' returns, so we can't tell
45 *     the difference between partial and no conversions.
46 *   - returns english strings
47 *   - can't set the base, or find where the conversion ended
48 */
49long long
50strtonum(const char * __restrict ptr, long long lo, long long hi,
51    const char ** __restrict res)
52{
53	int e;
54	intmax_t rv;
55	const char *resp;
56
57	if (res == NULL)
58		res = &resp;
59
60	rv = strtoi(ptr, NULL, 0, lo, hi, &e);
61	if (e == 0) {
62		*res = NULL;
63		return rv;
64	}
65	*res = e != ERANGE ? "invalid" : (rv == hi ? "too large" : "too small");
66	return 0;
67}
68