NetBSD/gnu/libexec/uucp/libuucp/strtol.c

176 lines
3.9 KiB
C

/* Copyright (C) 1991 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 59 Temple Place -
Suite 330, Boston, MA 02111-1307, USA.
This file was modified slightly by Ian Lance Taylor, May 1992, for
Taylor UUCP. */
#include "uucp.h"
#include <ctype.h>
#include <errno.h>
#if HAVE_LIMITS_H
#include <limits.h>
#else
#define ULONG_MAX 4294967295
#define LONG_MIN (- LONG_MAX - 1)
#define LONG_MAX 2147483647
#endif
#ifndef UNSIGNED
#define UNSIGNED 0
#endif
/* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
If BASE is 0 the base is determined by the presence of a leading
zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
If BASE is < 2 or > 36, it is reset to 10.
If ENDPTR is not NULL, a pointer to the character after the last
one converted is stored in *ENDPTR. */
#if UNSIGNED
unsigned long int
#define strtol strtoul
#else
long int
#endif
strtol (nptr, endptr, base)
const char *nptr;
char **endptr;
int base;
{
int negative;
register unsigned long int cutoff;
register unsigned int cutlim;
register unsigned long int i;
register const char *s;
register unsigned int c;
const char *save;
int overflow;
if (base < 0 || base == 1 || base > 36)
base = 10;
s = nptr;
/* Skip white space. */
while (isspace(BUCHAR (*s)))
++s;
if (*s == '\0')
goto noconv;
/* Check for a sign. */
if (*s == '-')
{
negative = 1;
++s;
}
else if (*s == '+')
{
negative = 0;
++s;
}
else
negative = 0;
if (base == 16
&& s[0] == '0'
&& (s[1] == 'x' || s[1] == 'X'))
s += 2;
/* If BASE is zero, figure it out ourselves. */
if (base == 0)
if (*s == '0')
{
if (s[1] == 'x' || s[1] == 'X')
{
s += 2;
base = 16;
}
else
base = 8;
}
else
base = 10;
/* Save the pointer so we can check later if anything happened. */
save = s;
cutoff = ULONG_MAX / (unsigned long int) base;
cutlim = ULONG_MAX % (unsigned long int) base;
overflow = 0;
i = 0;
for (c = BUCHAR (*s); c != '\0'; c = BUCHAR (*++s))
{
if (isdigit(c))
c -= '0';
else if (islower(c))
c = c - 'a' + 10;
else if (isupper(c))
c = c - 'A' + 10;
else
break;
if (c >= base)
break;
/* Check for overflow. */
if (i > cutoff || (i == cutoff && c > cutlim))
overflow = 1;
else
{
i *= (unsigned long int) base;
i += c;
}
}
/* Check if anything actually happened. */
if (s == save)
goto noconv;
/* Store in ENDPTR the address of one character
past the last character we converted. */
if (endptr != NULL)
*endptr = (char *) s;
#if !UNSIGNED
/* Check for a value that is within the range of
`unsigned long int', but outside the range of `long int'. */
if (i > (negative ?
- (unsigned long int) LONG_MIN : (unsigned long int) LONG_MAX))
overflow = 1;
#endif
if (overflow)
{
errno = ERANGE;
#if UNSIGNED
return ULONG_MAX;
#else
return negative ? LONG_MIN : LONG_MAX;
#endif
}
/* Return the result of the appropriate sign. */
return (negative ? - i : i);
noconv:
/* There was no number to convert. */
if (endptr != NULL)
*endptr = (char *) nptr;
return 0L;
}