strtonum.c revision 1.3 
1/*	$NetBSD: strtonum.c,v 1.3 2015/02/05 16:01:38 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 1.3 2015/02/05 16:01:38 christos Exp $");
33
34#define _OPENBSD_SOURCE
35#include <stdio.h>
36#include <stdlib.h>
37#include <errno.h>
38#include <inttypes.h>
39
40long long
41strtonum(const char *nptr, long long minval, long long maxval,
42         const char **errstr)
43{
44	int e;
45	long long rv;
46	const char *resp;
47
48	if (errstr == NULL)
49		errstr = &resp;
50
51	rv = (long long)strtoi(nptr, NULL, 0, minval, maxval, &e);
52
53	if (e == 0) {
54		*errstr = NULL;
55		return rv;
56	}
57
58	if (e == ERANGE)
59		*errstr = (rv == maxval ? "too large" : "too small");
60	else
61		*errstr = "invalid";
62
63	return 0;
64}
65