lib/libutil/dehumanize_number.c

   1 /*      $NetBSD: dehumanize_number.c,v 1.3 2008/04/28 20:22:59 martin Exp $     */
   2 /*      $DragonFly: src/lib/libutil/dehumanize_number.c,v 1.2 2008/10/29 22:03:12 swildner Exp $        */
   3
   4 /*
   5  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
   6  * All rights reserved.
   7  *
   8  * This code is derived from software contributed to The NetBSD Foundation
   9  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
  10  * 2005 program.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <inttypes.h>
  35 #include <ctype.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <errno.h>
  39 #include <limits.h>
  40
  41 #include "libutil.h"
  42
  43 /*
  44  * Converts the number given in 'str', which may be given in a humanized
  45  * form (as described in humanize_number(3), but with some limitations),
  46  * to an int64_t without units.
  47  * In case of success, 0 is returned and *size holds the value.
  48  * Otherwise, -1 is returned and *size is untouched.
  49  *
  50  * TODO: Internationalization, SI units.
  51  */
  52 int
  53 dehumanize_number(const char *str, int64_t *size)
  54 {
  55         char *ep, unit;
  56         const char *delimit;
  57         long multiplier;
  58         long long tmp, tmp2;
  59         size_t len;
  60
  61         len = strlen(str);
  62         if (len == 0) {
  63                 errno = EINVAL;
  64                 return -1;
  65         }
  66
  67         multiplier = 1;
  68
  69         unit = str[len - 1];
  70         if (isalpha((unsigned char)unit)) {
  71                 switch (tolower((unsigned char)unit)) {
  72                 case 'b':
  73                         multiplier = 1;
  74                         break;
  75
  76                 case 'k':
  77                         multiplier = 1024;
  78                         break;
  79
  80                 case 'm':
  81                         multiplier = 1024 * 1024;
  82                         break;
  83
  84                 case 'g':
  85                         multiplier = 1024 * 1024 * 1024;
  86                         break;
  87
  88                 default:
  89                         errno = EINVAL;
  90                         return -1; /* Invalid suffix. */
  91                 }
  92
  93                 delimit = &str[len - 1];
  94         } else
  95                 delimit = NULL;
  96
  97         errno = 0;
  98         tmp = strtoll(str, &ep, 10);
  99         if (str[0] == '\0' || (ep != delimit && *ep != '\0'))
 100                 return -1; /* Not a number. */
 101         else if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
 102                 return -1; /* Out of range. */
 103
 104         tmp2 = tmp * multiplier;
 105         tmp2 = tmp2 / multiplier;
 106         if (tmp != tmp2) {
 107                 errno = ERANGE;
 108                 return -1; /* Out of range. */
 109         }
 110         *size = tmp * multiplier;
 111
 112         return 0;
 113 }