xref: /freebsd/lib/libutil/expand_number.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*-
2  * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>
3  * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/types.h>
32 #include <ctype.h>
33 #include <errno.h>
34 #include <libutil.h>
35 #include <stdint.h>
36 
37 /*
38  * Convert an expression of the following forms to a int64_t.
39  * 	1) A positive decimal number.
40  *	2) A positive decimal number followed by a 'b' or 'B' (mult by 1).
41  *	3) A positive decimal number followed by a 'k' or 'K' (mult by 1 << 10).
42  *	4) A positive decimal number followed by a 'm' or 'M' (mult by 1 << 20).
43  *	5) A positive decimal number followed by a 'g' or 'G' (mult by 1 << 30).
44  *	6) A positive decimal number followed by a 't' or 'T' (mult by 1 << 40).
45  *	7) A positive decimal number followed by a 'p' or 'P' (mult by 1 << 50).
46  *	8) A positive decimal number followed by a 'e' or 'E' (mult by 1 << 60).
47  */
48 int
49 expand_number(const char *buf, int64_t *num)
50 {
51 	static const char unit[] = "bkmgtpe";
52 	char *endptr, s;
53 	int64_t number;
54 	int i;
55 
56 	number = strtoimax(buf, &endptr, 0);
57 
58 	if (endptr == buf) {
59 		/* No valid digits. */
60 		errno = EINVAL;
61 		return (-1);
62 	}
63 
64 	if (*endptr == '\0') {
65 		/* No unit. */
66 		*num = number;
67 		return (0);
68 	}
69 
70 	s = tolower(*endptr);
71 	switch (s) {
72 	case 'b':
73 	case 'k':
74 	case 'm':
75 	case 'g':
76 	case 't':
77 	case 'p':
78 	case 'e':
79 		break;
80 	default:
81 		/* Unrecognized unit. */
82 		errno = EINVAL;
83 		return (-1);
84 	}
85 
86 	for (i = 0; unit[i] != '\0'; i++) {
87 		if (s == unit[i])
88 			break;
89 		if ((number < 0 && (number << 10) > number) ||
90 		    (number >= 0 && (number << 10) < number)) {
91 			errno = ERANGE;
92 			return (-1);
93 		}
94 		number <<= 10;
95 	}
96 
97 	*num = number;
98 	return (0);
99 }
100