Utilities/cmcurl/strtoofft.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
   9  *
  10  * This software is licensed as described in the file COPYING, which
  11  * you should have received as part of this distribution. The terms
  12  * are also available at http://curl.haxx.se/docs/copyright.html.
  13  *
  14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15  * copies of the Software, and permit persons to whom the Software is
  16  * furnished to do so, under the terms of the COPYING file.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  * $Id: strtoofft.c,v 1.2 2007-03-15 19:22:13 andy Exp $
  22  ***************************************************************************/
  23
  24 #include "setup.h"
  25 #include "strtoofft.h"
  26
  27 /*
  28  * NOTE:
  29  *
  30  * In the ISO C standard (IEEE Std 1003.1), there is a strtoimax() function we
  31  * could use in case strtoll() doesn't exist...  See
  32  * http://www.opengroup.org/onlinepubs/009695399/functions/strtoimax.html
  33  */
  34
  35 #ifdef NEED_CURL_STRTOLL
  36 #include <stdlib.h>
  37 #include <ctype.h>
  38 #include <errno.h>
  39
  40 static int get_char(char c, int base);
  41
  42 /**
  43  * Emulated version of the strtoll function.  This extracts a long long
  44  * value from the given input string and returns it.
  45  */
  46 curl_off_t
  47 curlx_strtoll(const char *nptr, char **endptr, int base)
  48 {
  49   char *end;
  50   int is_negative = 0;
  51   int overflow;
  52   int i;
  53   curl_off_t value = 0;
  54   curl_off_t newval;
  55
  56   /* Skip leading whitespace. */
  57   end = (char *)nptr;
  58   while (ISSPACE(end[0])) {
  59     end++;
  60   }
  61
  62   /* Handle the sign, if any. */
  63   if (end[0] == '-') {
  64     is_negative = 1;
  65     end++;
  66   }
  67   else if (end[0] == '+') {
  68     end++;
  69   }
  70   else if (end[0] == '\0') {
  71     /* We had nothing but perhaps some whitespace -- there was no number. */
  72     if (endptr) {
  73       *endptr = end;
  74     }
  75     return 0;
  76   }
  77
  78   /* Handle special beginnings, if present and allowed. */
  79   if (end[0] == '0' && end[1] == 'x') {
  80     if (base == 16 || base == 0) {
  81       end += 2;
  82       base = 16;
  83     }
  84   }
  85   else if (end[0] == '0') {
  86     if (base == 8 || base == 0) {
  87       end++;
  88       base = 8;
  89     }
  90   }
  91
  92   /* Matching strtol, if the base is 0 and it doesn't look like
  93    * the number is octal or hex, we assume it's base 10.
  94    */
  95   if (base == 0) {
  96     base = 10;
  97   }
  98
  99   /* Loop handling digits. */
 100   value = 0;
 101   overflow = 0;
 102   for (i = get_char(end[0], base);
 103        i != -1;
 104        end++, i = get_char(end[0], base)) {
 105     newval = base * value + i;
 106     if (newval < value) {
 107       /* We've overflowed. */
 108       overflow = 1;
 109       break;
 110     }
 111     else
 112       value = newval;
 113   }
 114
 115   if (!overflow) {
 116     if (is_negative) {
 117       /* Fix the sign. */
 118       value *= -1;
 119     }
 120   }
 121   else {
 122     if (is_negative)
 123       value = CURL_LLONG_MIN;
 124     else
 125       value = CURL_LLONG_MAX;
 126
 127     errno = ERANGE;
 128   }
 129
 130   if (endptr)
 131     *endptr = end;
 132
 133   return value;
 134 }
 135
 136 /**
 137  * Returns the value of c in the given base, or -1 if c cannot
 138  * be interpreted properly in that base (i.e., is out of range,
 139  * is a null, etc.).
 140  *
 141  * @param c     the character to interpret according to base
 142  * @param base  the base in which to interpret c
 143  *
 144  * @return  the value of c in base, or -1 if c isn't in range
 145  */
 146 static int get_char(char c, int base)
 147 {
 148   int value = -1;
 149   if (c <= '9' && c >= '0') {
 150     value = c - '0';
 151   }
 152   else if (c <= 'Z' && c >= 'A') {
 153     value = c - 'A' + 10;
 154   }
 155   else if (c <= 'z' && c >= 'a') {
 156     value = c - 'a' + 10;
 157   }
 158
 159   if (value >= base) {
 160     value = -1;
 161   }
 162
 163   return value;
 164 }
 165 #endif  /* Only present if we need strtoll, but don't have it. */