lib/sh/strtol.c

   1 /* strtol - convert string representation of a number into a long integer value. */
   2
   3 /* Copyright (C) 1991,92,94,95,96,97,98,99,2000,2001 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bush, the Bourne Again SHell.
   6
   7    Bush is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bush is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bush.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include <config.h>
  22
  23 #if !defined (HAVE_STRTOL)
  24
  25 #include <chartypes.h>
  26 #include <errno.h>
  27
  28 #ifndef errno
  29 extern int errno;
  30 #endif
  31
  32 #ifndef __set_errno
  33 #  define __set_errno(Val) errno = (Val)
  34 #endif
  35
  36 #ifdef HAVE_LIMITS_H
  37 #  include <limits.h>
  38 #endif
  39
  40 #include <typemax.h>
  41
  42 #include <stdc.h>
  43 #include <bushansi.h>
  44
  45 #ifndef NULL
  46 #  define NULL 0
  47 #endif
  48
  49 /* Nonzero if we are defining `strtoul' or `strtoull', operating on
  50    unsigned integers.  */
  51 #ifndef UNSIGNED
  52 #  define UNSIGNED 0
  53 #  define INT LONG int
  54 #else
  55 #  define INT unsigned LONG int
  56 #endif
  57
  58 #if UNSIGNED
  59 #  ifdef QUAD
  60 #    define strtol strtoull
  61 #  else
  62 #    define strtol strtoul
  63 #  endif
  64 #else
  65 #  ifdef QUAD
  66 #    define strtol strtoll
  67 #  endif
  68 #endif
  69
  70 /* If QUAD is defined, we are defining `strtoll' or `strtoull',
  71    operating on `long long ints.  */
  72
  73 #ifdef QUAD
  74 #  define LONG long long
  75 #  define STRTOL_LONG_MIN LLONG_MIN
  76 #  define STRTOL_LONG_MAX LLONG_MAX
  77 #  define STRTOL_ULONG_MAX ULLONG_MAX
  78 #else   /* !QUAD */
  79 #  define LONG long
  80 #  define STRTOL_LONG_MIN LONG_MIN
  81 #  define STRTOL_LONG_MAX LONG_MAX
  82 #  define STRTOL_ULONG_MAX ULONG_MAX
  83 #endif
  84
  85 /* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
  86    If BASE is 0 the base is determined by the presence of a leading
  87    zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
  88    If BASE is < 2 or > 36, it is no longer reset to 10; EINVAL is returned.
  89    If ENDPTR is not NULL, a pointer to the character after the last
  90    one converted is stored in *ENDPTR.  */
  91
  92 INT
  93 strtol (nptr, endptr, base)
  94      const char *nptr;
  95      char **endptr;
  96      int base;
  97 {
  98   int negative;
  99   register unsigned LONG int cutoff;
 100   register unsigned int cutlim;
 101   register unsigned LONG int i;
 102   register const char *s;
 103   register unsigned char c;
 104   const char *save, *end;
 105   int overflow;
 106
 107   if (base < 0 || base == 1 || base > 36)
 108     {
 109       __set_errno (EINVAL);
 110       return 0;
 111     }
 112
 113   save = s = nptr;
 114
 115   /* Skip white space.  */
 116   while (ISSPACE ((unsigned char)*s))
 117     ++s;
 118   if (*s == '\0')
 119     goto noconv;
 120
 121   /* Check for a sign.  */
 122   if (*s == '-' || *s == '+')
 123     {
 124       negative = (*s == '-');
 125       ++s;
 126     }
 127   else
 128     negative = 0;
 129
 130   /* Recognize number prefix and if BASE is zero, figure it out ourselves.  */
 131   if (*s == '0')
 132     {
 133       if ((base == 0 || base == 16) && TOUPPER ((unsigned char) s[1]) == 'X')
 134         {
 135           s += 2;
 136           base = 16;
 137         }
 138       else if (base == 0)
 139         base = 8;
 140     }
 141   else if (base == 0)
 142     base = 10;
 143
 144   /* Save the pointer so we can check later if anything happened.  */
 145   save = s;
 146
 147   end = NULL;
 148
 149   cutoff = STRTOL_ULONG_MAX / (unsigned LONG int) base;
 150   cutlim = STRTOL_ULONG_MAX % (unsigned LONG int) base;
 151
 152   overflow = 0;
 153   i = 0;
 154   c = *s;
 155   if (sizeof (long int) != sizeof (LONG int))
 156     {
 157       unsigned long int j = 0;
 158       unsigned long int jmax = ULONG_MAX / base;
 159
 160       for (;c != '\0'; c = *++s)
 161         {
 162           if (s == end)
 163             break;
 164           if (DIGIT (c))
 165             c -= '0';
 166           else if (ISALPHA (c))
 167             c = TOUPPER (c) - 'A' + 10;
 168           else
 169             break;
 170
 171           if ((int) c >= base)
 172             break;
 173           /* Note that we never can have an overflow.  */
 174           else if (j >= jmax)
 175             {
 176               /* We have an overflow.  Now use the long representation.  */
 177               i = (unsigned LONG int) j;
 178               goto use_long;
 179             }
 180           else
 181             j = j * (unsigned long int) base + c;
 182         }
 183
 184       i = (unsigned LONG int) j;
 185     }
 186   else
 187     for (;c != '\0'; c = *++s)
 188       {
 189         if (s == end)
 190           break;
 191         if (DIGIT (c))
 192           c -= '0';
 193         else if (ISALPHA (c))
 194           c = TOUPPER (c) - 'A' + 10;
 195         else
 196           break;
 197         if ((int) c >= base)
 198           break;
 199         /* Check for overflow.  */
 200         if (i > cutoff || (i == cutoff && c > cutlim))
 201           overflow = 1;
 202         else
 203           {
 204           use_long:
 205             i *= (unsigned LONG int) base;
 206             i += c;
 207           }
 208       }
 209
 210   /* Check if anything actually happened.  */
 211   if (s == save)
 212     goto noconv;
 213
 214   /* Store in ENDPTR the address of one character
 215      past the last character we converted.  */
 216   if (endptr != NULL)
 217     *endptr = (char *) s;
 218
 219 #if !UNSIGNED
 220   /* Check for a value that is within the range of
 221      `unsigned LONG int', but outside the range of `LONG int'.  */
 222   if (overflow == 0
 223       && i > (negative
 224               ? -((unsigned LONG int) (STRTOL_LONG_MIN + 1)) + 1
 225               : (unsigned LONG int) STRTOL_LONG_MAX))
 226     overflow = 1;
 227 #endif
 228
 229   if (overflow)
 230     {
 231       __set_errno (ERANGE);
 232 #if UNSIGNED
 233       return STRTOL_ULONG_MAX;
 234 #else
 235       return negative ? STRTOL_LONG_MIN : STRTOL_LONG_MAX;
 236 #endif
 237     }
 238
 239   /* Return the result of the appropriate sign.  */
 240   return negative ? -i : i;
 241
 242 noconv:
 243   /* We must handle a special case here: the base is 0 or 16 and the
 244      first two characters are '0' and 'x', but the rest are no
 245      hexadecimal digits.  This is no error case.  We return 0 and
 246      ENDPTR points to the `x`.  */
 247   if (endptr != NULL)
 248     {
 249       if (save - nptr >= 2 && TOUPPER ((unsigned char) save[-1]) == 'X' && save[-2] == '0')
 250         *endptr = (char *) &save[-1];
 251       else
 252         /*  There was no number to convert.  */
 253         *endptr = (char *) nptr;
 254     }
 255
 256   return 0L;
 257 }
 258
 259 #endif /* !HAVE_STRTOL */