strtol.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI" /* from S5R2 2.1 */
/*LINTLIBRARY*/
#include <ctype.h>
#define DIGIT(x) (isdigit(x) ? (x) - '0' : \
islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')
#define MBASE ('z' - 'a' + 1 + 10)
long
strtol(str, ptr, base)
register char *str;
char **ptr;
register int base;
{
register long val;
register int c;
int xx, neg = 0;
if (ptr != (char **)0)
*ptr = str; /* in case no number is formed */
if (base < 0 || base > MBASE)
return (0); /* base is invalid -- should be a fatal error */
if (!isalnum(c = *str)) {
while (isspace(c))
c = *++str;
switch (c) {
case '-':
neg++;
case '+': /* fall-through */
c = *++str;
}
}
if (base == 0)
if (c != '0')
base = 10;
else if (str[1] == 'x' || str[1] == 'X')
base = 16;
else
base = 8;
/*
* for any base > 10, the digits incrementally following
* 9 are assumed to be "abc...z" or "ABC...Z"
*/
if (!isalnum(c) || (xx = DIGIT(c)) >= base)
return (0); /* no number formed */
if (base == 16 && c == '0' && isxdigit(str[2]) &&
(str[1] == 'x' || str[1] == 'X'))
c = *(str += 2); /* skip over leading "0x" or "0X" */
for (val = -DIGIT(c); isalnum(c = *++str) && (xx = DIGIT(c)) < base; )
/* accumulate neg avoids surprises near MAXLONG */
val = base * val - xx;
if (ptr != (char **)0)
*ptr = str;
return (neg ? val : -val);
}