lib/libc/gen/dehumanize_number.c

   1 /*      $NetBSD: dehumanize_number.c,v 1.4 2012/03/13 21:13:34 christos 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 1.4 2012/03/13 21:13:34 christos 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 }