xref: /dragonfly/lib/libutil/dehumanize_number.c (revision 19fe1c42)
1 /*	$NetBSD: dehumanize_number.c,v 1.3 2008/04/28 20:22:59 martin Exp $	*/
2 /*	$DragonFly: src/lib/libutil/dehumanize_number.c,v 1.2 2008/10/29 22:03:12 swildner Exp $	*/
3 
4 /*
5  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
10  * 2005 program.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <inttypes.h>
35 #include <ctype.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <errno.h>
39 #include <limits.h>
40 
41 #include "libutil.h"
42 
43 /*
44  * Converts the number given in 'str', which may be given in a humanized
45  * form (as described in humanize_number(3), but with some limitations),
46  * to an int64_t without units.
47  * In case of success, 0 is returned and *size holds the value.
48  * Otherwise, -1 is returned and *size is untouched.
49  *
50  * TODO: Internationalization, SI units.
51  */
52 int
53 dehumanize_number(const char *str, int64_t *size)
54 {
55 	char *ep, unit;
56 	const char *delimit;
57 	long multiplier;
58 	long long tmp, tmp2;
59 	size_t len;
60 
61 	len = strlen(str);
62 	if (len == 0) {
63 		errno = EINVAL;
64 		return -1;
65 	}
66 
67 	multiplier = 1;
68 
69 	unit = str[len - 1];
70 	if (isalpha((unsigned char)unit)) {
71 		switch (tolower((unsigned char)unit)) {
72 		case 'b':
73 			multiplier = 1;
74 			break;
75 
76 		case 'k':
77 			multiplier = 1024;
78 			break;
79 
80 		case 'm':
81 			multiplier = 1024 * 1024;
82 			break;
83 
84 		case 'g':
85 			multiplier = 1024 * 1024 * 1024;
86 			break;
87 
88 		default:
89 			errno = EINVAL;
90 			return -1; /* Invalid suffix. */
91 		}
92 
93 		delimit = &str[len - 1];
94 	} else
95 		delimit = NULL;
96 
97 	errno = 0;
98 	tmp = strtoll(str, &ep, 10);
99 	if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
100 		return -1; /* Not a number. */
101 	else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
102 		return -1; /* Out of range. */
103 
104 	tmp2 = tmp * multiplier;
105 	tmp2 = tmp2 / multiplier;
106 	if (tmp != tmp2) {
107 		errno = ERANGE;
108 		return -1; /* Out of range. */
109 	}
110 	*size = tmp * multiplier;
111 
112 	return 0;
113 }
114