gnu/dist/groff/src/libs/libgroff/strtol.c

   1 /*      $NetBSD$        */
   2
   3 /* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2001
   4    Free Software Foundation, Inc.
   5      Written by James Clark (jjc@jclark.com)
   6
   7 This file is part of groff.
   8
   9 groff is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 2, or (at your option) any later
  12 version.
  13
  14 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License along
  20 with groff; see the file COPYING.  If not, write to the Free Software
  21 Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <errno.h>
  30
  31 #ifdef HAVE_LIMITS_H
  32 #include <limits.h>
  33 #endif
  34
  35 #ifndef LONG_MAX
  36 #define LONG_MAX  2147483647
  37 #endif
  38
  39 #ifndef LONG_MIN
  40 #define LONG_MIN (-LONG_MAX-1)
  41 #endif
  42
  43 #ifdef isascii
  44 #define ISASCII(c) isascii(c)
  45 #else
  46 #define ISASCII(c) (1)
  47 #endif
  48
  49 long strtol(str, ptr, base)
  50      char *str, **ptr;
  51      int base;
  52 {
  53   char *start = str;
  54   int neg = 0;
  55   long val;
  56   char *p;
  57   static char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
  58
  59   while (ISASCII((unsigned char)*str) && isspace((unsigned char)*str))
  60     str++;
  61
  62   if (*str == '-') {
  63     neg = 1;
  64     str++;
  65   }
  66   if (base == 0) {
  67     if (*str == '0') {
  68       if (str[1] == 'x' || str[1] == 'X') {
  69         str += 2;
  70         base = 16;
  71       }
  72       else
  73         base = 8;
  74     }
  75     else
  76       base = 10;
  77   }
  78   if (base < 2 || base > 36)
  79     base = 10;
  80   else if (base == 16 && *str == '0' && (str[1] == 'x' || str[1] == 'X'))
  81     str += 2;
  82
  83   p = strchr(digits, (ISASCII((unsigned char)*str)
  84                       && isupper((unsigned char)*str)
  85                       ? tolower((unsigned char)*str)
  86                       : *str));
  87   if (p == 0 || (val = (p - digits)) >= base) {
  88     if (base == 16 && str > start && (str[-1] == 'x' || str[-1] == 'X')) {
  89       if (ptr)
  90         *ptr = str - 1;
  91     }
  92     else {
  93       if (ptr)
  94         *ptr = start;
  95       errno = ERANGE;
  96     }
  97     return 0;
  98   }
  99   if (neg)
 100     val = -val;
 101
 102   while (*++str != '\0') {
 103     int n;
 104
 105     p = strchr(digits, (ISASCII((unsigned char)*str)
 106                         && isupper((unsigned char)*str)
 107                         ? tolower((unsigned char)*str) : *str));
 108     if (p == 0)
 109       break;
 110     n = p - digits;
 111     if (n >= base)
 112       break;
 113     if (neg) {
 114       if (-(unsigned long)val > (-(unsigned long)LONG_MIN - n)/base) {
 115         val = LONG_MIN;
 116         errno = ERANGE;
 117       }
 118       else
 119         val = val*base - n;
 120     }
 121     else {
 122       if (val > (LONG_MAX - n)/base) {
 123         val = LONG_MAX;
 124         errno = ERANGE;
 125       }
 126       else
 127         val = val*base + n;
 128     }
 129   }
 130
 131   if (ptr)
 132     *ptr = str;
 133
 134   return val;
 135 }