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dehumanize_number.c revision 1.3.8.2 
      1 /*	$NetBSD: dehumanize_number.c,v 1.3.8.2 2008/04/28 20:23:00 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 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 __RCSID("$NetBSD: dehumanize_number.c,v 1.3.8.2 2008/04/28 20:23:00 martin Exp $");
     35 #endif /* LIBC_SCCS and not lint */
     36 
     37 #include "namespace.h"
     38 #include <inttypes.h>
     39 #include <ctype.h>
     40 #include <stdlib.h>
     41 #include <string.h>
     42 #include <errno.h>
     43 #include <limits.h>
     44 
     45 /*
     46  * Converts the number given in 'str', which may be given in a humanized
     47  * form (as described in humanize_number(3), but with some limitations),
     48  * to an int64_t without units.
     49  * In case of success, 0 is returned and *size holds the value.
     50  * Otherwise, -1 is returned and *size is untouched.
     51  *
     52  * TODO: Internationalization, SI units.
     53  */
     54 int
     55 dehumanize_number(const char *str, int64_t *size)
     56 {
     57 	char *ep, unit;
     58 	const char *delimit;
     59 	long multiplier;
     60 	long long tmp, tmp2;
     61 	size_t len;
     62 
     63 	len = strlen(str);
     64 	if (len == 0) {
     65 		errno = EINVAL;
     66 		return -1;
     67 	}
     68 
     69 	multiplier = 1;
     70 
     71 	unit = str[len - 1];
     72 	if (isalpha((unsigned char)unit)) {
     73 		switch (tolower((unsigned char)unit)) {
     74 		case 'b':
     75 			multiplier = 1;
     76 			break;
     77 
     78 		case 'k':
     79 			multiplier = 1024;
     80 			break;
     81 
     82 		case 'm':
     83 			multiplier = 1024 * 1024;
     84 			break;
     85 
     86 		case 'g':
     87 			multiplier = 1024 * 1024 * 1024;
     88 			break;
     89 
     90 		default:
     91 			errno = EINVAL;
     92 			return -1; /* Invalid suffix. */
     93 		}
     94 
     95 		delimit = &str[len - 1];
     96 	} else
     97 		delimit = NULL;
     98 
     99 	errno = 0;
    100 	tmp = strtoll(str, &ep, 10);
    101 	if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
    102 		return -1; /* Not a number. */
    103 	else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
    104 		return -1; /* Out of range. */
    105 
    106 	tmp2 = tmp * multiplier;
    107 	tmp2 = tmp2 / multiplier;
    108 	if (tmp != tmp2) {
    109 		errno = ERANGE;
    110 		return -1; /* Out of range. */
    111 	}
    112 	*size = tmp * multiplier;
    113 
    114 	return 0;
    115 }
    116