1 /*	$OpenBSD: strtonum.c,v 1.6 2004/08/03 19:38:01 millert Exp $	*/
2 
3 /*
4  * Copyright (c) 2004 Ted Unangst and Todd Miller
5  * All rights reserved.
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <errno.h>
21 #include <limits.h>
22 #include <stdlib.h>
23 
24 #define INVALID 	1
25 #define TOOSMALL 	2
26 #define TOOLARGE 	3
27 
28 long long
29 strtonum(const char *numstr, long long minval, long long maxval,
30     const char **errstrp)
31 {
32 	long long ll = 0;
33 	char *ep;
34 	int error = 0;
35 	struct errval {
36 		const char *errstr;
37 		int err;
38 	} ev[4] = {
39 		{ NULL,		0 },
40 		{ "invalid",	EINVAL },
41 		{ "too small",	ERANGE },
42 		{ "too large",	ERANGE },
43 	};
44 
45 	ev[0].err = errno;
46 	errno = 0;
47 	if (minval > maxval)
48 		error = INVALID;
49 	else {
50 		ll = strtoll(numstr, &ep, 10);
51 		if (numstr == ep || *ep != '\0')
52 			error = INVALID;
53 		else if ((ll == LLONG_MIN && errno == ERANGE) || ll < minval)
54 			error = TOOSMALL;
55 		else if ((ll == LLONG_MAX && errno == ERANGE) || ll > maxval)
56 			error = TOOLARGE;
57 	}
58 	if (errstrp != NULL)
59 		*errstrp = ev[error].errstr;
60 	errno = ev[error].err;
61 	if (error)
62 		ll = 0;
63 
64 	return (ll);
65 }