xref: /dragonfly/lib/libutil/dehumanize_number.c (revision 82730a9c)
1 /*	$NetBSD: dehumanize_number.c,v 1.3 2008/04/28 20:22:59 martin Exp $	*/
2 
3 /*
4  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
9  * 2005 program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <inttypes.h>
34 #include <ctype.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <errno.h>
38 #include <limits.h>
39 
40 #include "libutil.h"
41 
42 /*
43  * Converts the number given in 'str', which may be given in a humanized
44  * form (as described in humanize_number(3), but with some limitations),
45  * to an int64_t without units.
46  * In case of success, 0 is returned and *size holds the value.
47  * Otherwise, -1 is returned and *size is untouched.
48  *
49  * TODO: Internationalization, SI units.
50  */
51 int
52 dehumanize_number(const char *str, int64_t *size)
53 {
54 	char *ep, unit;
55 	const char *delimit;
56 	long multiplier;
57 	long long tmp, tmp2;
58 	size_t len;
59 
60 	len = strlen(str);
61 	if (len == 0) {
62 		errno = EINVAL;
63 		return -1;
64 	}
65 
66 	multiplier = 1;
67 
68 	unit = str[len - 1];
69 	if (isalpha((unsigned char)unit)) {
70 		switch (tolower((unsigned char)unit)) {
71 		case 'e':
72 			multiplier *= 1024;
73 			/* FALLTHROUGH */
74 		case 'p':
75 			multiplier *= 1024;
76 			/* FALLTHROUGH */
77 		case 't':
78 			multiplier *= 1024;
79 			/* FALLTHROUGH */
80 		case 'g':
81 			multiplier *= 1024;
82 			/* FALLTHROUGH */
83 		case 'm':
84 			multiplier *= 1024;
85 			/* FALLTHROUGH */
86 		case 'k':
87 			multiplier *= 1024;
88 			/* FALLTHROUGH */
89 		case 'b':
90 			break;
91 
92 		default:
93 			errno = EINVAL;
94 			return -1; /* Invalid suffix. */
95 		}
96 
97 		delimit = &str[len - 1];
98 	} else
99 		delimit = NULL;
100 
101 	errno = 0;
102 	tmp = strtoll(str, &ep, 10);
103 	if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
104 		return -1; /* Not a number. */
105 	else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
106 		return -1; /* Out of range. */
107 
108 	tmp2 = tmp * multiplier;
109 	tmp2 = tmp2 / multiplier;
110 	if (tmp != tmp2) {
111 		errno = ERANGE;
112 		return -1; /* Out of range. */
113 	}
114 	*size = tmp * multiplier;
115 
116 	return 0;
117 }
118