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dehumanize_number.c revision 1.3.4.1 
      1 /*	$NetBSD: dehumanize_number.c,v 1.3.4.1 2012/04/17 00:05:18 yamt 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 1.3.4.1 2012/04/17 00:05:18 yamt 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