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