xref: /minix3/lib/libc/gen/dehumanize_number.c (revision 0b98e8aad89f2bd4ba80b523d73cf29e9dd82ce1)
1 /*	$NetBSD: dehumanize_number.c,v 1.4 2012/03/13 21:13:34 christos 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 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: dehumanize_number.c,v 1.4 2012/03/13 21:13:34 christos Exp $");
35 #endif /* LIBC_SCCS and not lint */
36 
37 #include "namespace.h"
38 #include <assert.h>
39 #include <inttypes.h>
40 #include <ctype.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <errno.h>
44 #include <limits.h>
45 
46 /*
47  * Converts the number given in 'str', which may be given in a humanized
48  * form (as described in humanize_number(3), but with some limitations),
49  * to an int64_t without units.
50  * In case of success, 0 is returned and *size holds the value.
51  * Otherwise, -1 is returned and *size is untouched.
52  *
53  * TODO: Internationalization, SI units.
54  */
55 int
56 dehumanize_number(const char *str, int64_t *size)
57 {
58 	char *ep, unit;
59 	const char *delimit;
60 	long multiplier;
61 	long long tmp, tmp2;
62 	size_t len;
63 
64 	len = strlen(str);
65 	if (len == 0) {
66 		errno = EINVAL;
67 		return -1;
68 	}
69 
70 	multiplier = 1;
71 
72 	unit = str[len - 1];
73 	if (isalpha((unsigned char)unit)) {
74 		switch (tolower((unsigned char)unit)) {
75 		case 'b':
76 			multiplier = 1;
77 			break;
78 
79 		case 'k':
80 			multiplier = 1024;
81 			break;
82 
83 		case 'm':
84 			multiplier = 1024 * 1024;
85 			break;
86 
87 		case 'g':
88 			multiplier = 1024 * 1024 * 1024;
89 			break;
90 
91 		default:
92 			errno = EINVAL;
93 			return -1; /* Invalid suffix. */
94 		}
95 
96 		delimit = &str[len - 1];
97 	} else
98 		delimit = NULL;
99 
100 	errno = 0;
101 	tmp = strtoll(str, &ep, 10);
102 	if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
103 		return -1; /* Not a number. */
104 	else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
105 		return -1; /* Out of range. */
106 
107 	tmp2 = tmp * multiplier;
108 	tmp2 = tmp2 / multiplier;
109 	if (tmp != tmp2) {
110 		errno = ERANGE;
111 		return -1; /* Out of range. */
112 	}
113 	tmp *= multiplier;
114 	_DIAGASSERT(__type_fit(int64_t, tmp));
115 	*size = (int64_t)tmp;
116 
117 	return 0;
118 }
119