xref: /netbsd-src/lib/libc/stdlib/strtonum.c (revision f1987b28c87ee37690268b93ba1b11ed8d571305)
1 /*	$NetBSD: strtonum.c,v 1.7 2024/01/20 16:13:39 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 1.7 2024/01/20 16:13:39 christos Exp $");
33 
34 #include "namespace.h"
35 
36 #define _OPENBSD_SOURCE
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <errno.h>
40 #include <inttypes.h>
41 
42 long long
strtonum(const char * nptr,long long minval,long long maxval,const char ** errstr)43 strtonum(const char *nptr, long long minval, long long maxval,
44          const char **errstr)
45 {
46 	int e;
47 	long long rv;
48 	const char *resp;
49 	char *eptr;
50 
51 	if (errstr == NULL)
52 		errstr = &resp;
53 
54 	if (minval > maxval)
55 		goto out;
56 
57 	rv = (long long)strtoi(nptr, &eptr, 10, minval, maxval, &e);
58 
59 	switch (e) {
60 	case 0:
61 		*errstr = NULL;
62 		return rv;
63 	case ECANCELED:
64 	case ENOTSUP:
65 		goto out;
66 	case ERANGE:
67 		if (*eptr)
68 			goto out;
69 		*errstr = rv == maxval ? "too large" : "too small";
70 		return 0;
71 	default:
72 		abort();
73 	}
74 
75 out:
76 	*errstr = "invalid";
77 	return 0;
78 }
79