compiler/stdc/strtol.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     C99 function strtol().
   6 */
   7
   8 #include <ctype.h>
   9 #include <errno.h>
  10 #ifndef AROS_NO_LIMITS_H
  11 #       include <limits.h>
  12 #else
  13 #       define LONG_MAX 2147483647L
  14 #       define LONG_MIN (-LONG_MAX - 1L)
  15 #endif
  16
  17 /*****************************************************************************
  18
  19     NAME */
  20 #include <stdlib.h>
  21
  22         long strtol (
  23
  24 /*  SYNOPSIS */
  25         const char * str,
  26         char      ** endptr,
  27         int          base)
  28
  29 /*  FUNCTION
  30         Convert a string of digits into an integer according to the
  31         given base.
  32
  33     INPUTS
  34         str - The string which should be converted. Leading
  35                 whitespace are ignored. The number may be prefixed
  36                 by a '+' or '-'. If base is above 10, then the
  37                 alphabetic characters from 'A' are used to specify
  38                 digits above 9 (ie. 'A' or 'a' is 10, 'B' or 'b' is
  39                 11 and so on until 'Z' or 'z' is 35).
  40         endptr - If this is non-NULL, then the address of the first
  41                 character after the number in the string is stored
  42                 here.
  43         base - The base for the number. May be 0 or between 2 and 36,
  44                 including both. 0 means to autodetect the base. strtoul()
  45                 selects the base by inspecting the first characters
  46                 of the string. If they are "0x", then base 16 is
  47                 assumed. If they are "0", then base 8 is assumed. Any
  48                 other digit will assume base 10. This is like in C.
  49
  50                 If you give base 16, then an optional "0x" may
  51                 precede the number in the string.
  52
  53     RESULT
  54         The value of the string. The first character after the number
  55         is returned in *endptr, if endptr is non-NULL. If no digits can
  56         be converted, *endptr contains str (if non-NULL) and 0 is
  57         returned.
  58
  59     NOTES
  60
  61     EXAMPLE
  62         // returns 1, ptr points to the 0-Byte
  63         strol ("  \t +0x1", &ptr, 0);
  64
  65         // Returns 15. ptr points to the a
  66         strol ("017a", &ptr, 0);
  67
  68         // Returns 215 (5*36 + 35)
  69         strol ("5z", &ptr, 36);
  70
  71     BUGS
  72
  73     SEE ALSO
  74         atof(), atoi(), atol(), strtod(), strtoul()
  75
  76     INTERNALS
  77
  78 ******************************************************************************/
  79 {
  80     long val    = 0;
  81     char        * ptr;
  82     char        * copy;
  83
  84     while (isspace (*str))
  85         str ++;
  86
  87     copy = (char *)str;
  88
  89     if (*str)
  90     {
  91         val = strtoul (str, &ptr, base);
  92
  93         if (endptr)
  94         {
  95             if (ptr == str)
  96                 str = copy;
  97             else
  98                 str = ptr;
  99         }
 100
 101         /* Remember: strtoul() has already done the sign conversion */
 102         if (*copy == '-')
 103         {
 104             if ((signed long)val > 0)
 105             {
 106 #ifndef STDC_STATIC
 107                 errno = ERANGE;
 108 #endif
 109                 val = LONG_MIN;
 110             }
 111         }
 112         else
 113         {
 114             if ((signed long)val < 0)
 115             {
 116 #ifndef STDC_STATIC
 117                 errno = ERANGE;
 118 #endif
 119                 val = LONG_MAX;
 120             }
 121         }
 122     }
 123
 124     if (endptr)
 125         *endptr = (char *)str;
 126
 127     return val;
 128 } /* strtol */
 129