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dehumanize_number.c revision 1.2 
      1 /*	$NetBSD: dehumanize_number.c,v 1.2 2007/12/14 17:32:47 xtraeme 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  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *        This product includes software developed by the NetBSD
     22  *        Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 #include <sys/cdefs.h>
     40 #if defined(LIBC_SCCS) && !defined(lint)
     41 __RCSID("$NetBSD: dehumanize_number.c,v 1.2 2007/12/14 17:32:47 xtraeme Exp $");
     42 #endif /* LIBC_SCCS and not lint */
     43 
     44 #include "namespace.h"
     45 #include <inttypes.h>
     46 #include <ctype.h>
     47 #include <stdlib.h>
     48 #include <string.h>
     49 #include <errno.h>
     50 #include <limits.h>
     51 
     52 /*
     53  * Converts the number given in 'str', which may be given in a humanized
     54  * form (as described in humanize_number(3), but with some limitations),
     55  * to an int64_t without units.
     56  * In case of success, 0 is returned and *size holds the value.
     57  * Otherwise, -1 is returned and *size is untouched.
     58  *
     59  * TODO: Internationalization, SI units.
     60  */
     61 int
     62 dehumanize_number(const char *str, int64_t *size)
     63 {
     64 	char *ep, unit;
     65 	const char *delimit;
     66 	long multiplier;
     67 	long long tmp, tmp2;
     68 	size_t len;
     69 
     70 	len = strlen(str);
     71 	if (len == 0) {
     72 		errno = EINVAL;
     73 		return -1;
     74 	}
     75 
     76 	multiplier = 1;
     77 
     78 	unit = str[len - 1];
     79 	if (isalpha((unsigned char)unit)) {
     80 		switch (tolower((unsigned char)unit)) {
     81 		case 'b':
     82 			multiplier = 1;
     83 			break;
     84 
     85 		case 'k':
     86 			multiplier = 1024;
     87 			break;
     88 
     89 		case 'm':
     90 			multiplier = 1024 * 1024;
     91 			break;
     92 
     93 		case 'g':
     94 			multiplier = 1024 * 1024 * 1024;
     95 			break;
     96 
     97 		default:
     98 			errno = EINVAL;
     99 			return -1; /* Invalid suffix. */
    100 		}
    101 
    102 		delimit = &str[len - 1];
    103 	} else
    104 		delimit = NULL;
    105 
    106 	errno = 0;
    107 	tmp = strtoll(str, &ep, 10);
    108 	if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
    109 		return -1; /* Not a number. */
    110 	else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
    111 		return -1; /* Out of range. */
    112 
    113 	tmp2 = tmp * multiplier;
    114 	tmp2 = tmp2 / multiplier;
    115 	if (tmp != tmp2) {
    116 		errno = ERANGE;
    117 		return -1; /* Out of range. */
    118 	}
    119 	*size = tmp * multiplier;
    120 
    121 	return 0;
    122 }
    123