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freebsd/contrib/groff/libgroff/strtol.c
1996-09-07 16:18:32 +00:00

132 lines
2.7 KiB
C

/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
Written by James Clark (jjc@jclark.com)
This file is part of groff.
groff is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
groff is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
with groff; see the file COPYING. If not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include <string.h>
#include <ctype.h>
#include <errno.h>
#ifndef errno
extern int errno;
#endif
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#ifndef LONG_MAX
#define LONG_MAX 2147483647
#endif
#ifndef LONG_MIN
#define LONG_MIN (-LONG_MAX-1)
#endif
#ifdef isascii
#define ISASCII(c) isascii(c)
#else
#define ISASCII(c) (1)
#endif
long strtol(str, ptr, base)
char *str, **ptr;
int base;
{
char *start = str;
int neg = 0;
long val;
char *p;
static char digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
while (ISASCII((unsigned char)*str) && isspace((unsigned char)*str))
str++;
if (*str == '-') {
neg = 1;
str++;
}
if (base == 0) {
if (*str == '0') {
if (str[1] == 'x' || str[1] == 'X') {
str += 2;
base = 16;
}
else
base = 8;
}
else
base = 10;
}
if (base < 2 || base > 36)
base = 10;
else if (base == 16 && *str == '0' && (str[1] == 'x' || str[1] == 'X'))
str += 2;
p = strchr(digits, (ISASCII((unsigned char)*str)
&& isupper((unsigned char)*str)
? tolower((unsigned char)*str)
: *str));
if (p == 0 || (val = (p - digits)) >= base) {
if (base == 16 && str > start && (str[-1] == 'x' || str[-1] == 'X')) {
if (ptr)
*ptr = str - 1;
}
else {
if (ptr)
*ptr = start;
errno = ERANGE;
}
return 0;
}
if (neg)
val = -val;
while (*++str != '\0') {
int n;
p = strchr(digits, (ISASCII((unsigned char)*str)
&& isupper((unsigned char)*str)
? tolower((unsigned char)*str) : *str));
if (p == 0)
break;
n = p - digits;
if (n >= base)
break;
if (neg) {
if (-(unsigned long)val > (-(unsigned long)LONG_MIN - n)/base) {
val = LONG_MIN;
errno = ERANGE;
}
else
val = val*base - n;
}
else {
if (val > (LONG_MAX - n)/base) {
val = LONG_MAX;
errno = ERANGE;
}
else
val = val*base + n;
}
}
if (ptr)
*ptr = str;
return val;
}