/* Copyright (C) 1991, 1992, 1994, 1995 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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* 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. */
#include "ctype.h"
int strtol (nptr, endptr, base)
const char *nptr;
char **endptr;
int base;
{
int negative;
register unsigned int cutoff;
register unsigned int cutlim;
register unsigned int i;
register const char *s;
register unsigned char c;
const char *save, *end;
int overflow;
if (base < 0 || base == 1 || base > 36)
base = 10;
save = s = nptr;
/* Skip white space. */
while (((unsigned char) *s) <= 32 && *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;
end = 0;
cutoff = 0x7FFFFFFF / (unsigned int) base;
cutlim = 0x7FFFFFFF % (unsigned int) base;
overflow = 0;
i = 0;
for (c = *s; c != '\0'; c = *++s) {
if (s == end)
break;
if (c >= '0' && c <= '9')
c -= '0';
else if (c >= 'A' && c <= 'Z')
c = c - 'A' + 10;
else if (c >= 'a' && c <= 'z')
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 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)
*endptr = (char *) s;
if (overflow)
return negative ? (int) 0x80000000 : (int) 0x7FFFFFFF;
/* Return the result of the appropriate sign. */
return (negative ? -i : i);
noconv:
/* We must handle a special case here: the base is 0 or 16 and the
first two characters and '0' and 'x', but the rest are no
hexadecimal digits. This is no error case. We return 0 and
ENDPTR points to the `x`. */
if (endptr) {
if (save - nptr >= 2 && tolower (save[-1]) == 'x' && save[-2] == '0')
*endptr = (char *) &save[-1];
else
/* There was no number to convert. */
*endptr = (char *) nptr;
}
return 0L;
}