[apple/libc.git] / stdlib / FreeBSD / strtol.c

/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strtol.c	8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdlib/strtol.c,v 1.20 2007/01/09 00:28:10 imp Exp $");

#include <limits.h>
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>


/*
 * Convert a string to a long integer.
 *
 * Assumes that the upper and lower case
 * alphabets and digits are each contiguous.
 */
long
strtol(const char * __restrict nptr, char ** __restrict endptr, int base)
{
	const char *s;
	unsigned long acc;
	char c;
	unsigned long cutoff;
	int neg, any, cutlim;

	/*
	 * Skip white space and pick up leading +/- sign if any.
	 * If base is 0, allow 0x for hex and 0 for octal, else
	 * assume decimal; if base is already 16, allow 0x.
	 */
	s = nptr;
	do {
		c = *s++;
	} while (isspace((unsigned char)c));
	if (c == '-') {
		neg = 1;
		c = *s++;
	} else {
		neg = 0;
		if (c == '+')
			c = *s++;
	}
	if ((base == 0 || base == 16) &&
	    c == '0' && (*s == 'x' || *s == 'X') &&
	    ((s[1] >= '0' && s[1] <= '9') ||
	    (s[1] >= 'A' && s[1] <= 'F') ||
	    (s[1] >= 'a' && s[1] <= 'f'))) {
		c = s[1];
		s += 2;
		base = 16;
	}
	if (base == 0)
		base = c == '0' ? 8 : 10;
	acc = any = 0;
	if (base < 2 || base > 36)
		goto noconv;

	/*
	 * Compute the cutoff value between legal numbers and illegal
	 * numbers.  That is the largest legal value, divided by the
	 * base.  An input number that is greater than this value, if
	 * followed by a legal input character, is too big.  One that
	 * is equal to this value may be valid or not; the limit
	 * between valid and invalid numbers is then based on the last
	 * digit.  For instance, if the range for longs is
	 * [-2147483648..2147483647] and the input base is 10,
	 * cutoff will be set to 214748364 and cutlim to either
	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
	 * the number is too big, and we will return a range error.
	 *
	 * Set 'any' if any `digits' consumed; make it negative to indicate
	 * overflow.
	 */
	cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
	    : LONG_MAX;
	cutlim = cutoff % base;
	cutoff /= base;
	for ( ; ; c = *s++) {
		if (c >= '0' && c <= '9')
			c -= '0';
		else if (c >= 'A' && c <= 'Z')
			c -= 'A' - 10;
		else if (c >= 'a' && c <= 'z')
			c -= 'a' - 10;
		else
			break;
		if (c >= base)
			break;
		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
			any = -1;
		else {
			any = 1;
			acc *= base;
			acc += c;
		}
	}
	if (any < 0) {
		acc = neg ? LONG_MIN : LONG_MAX;
		errno = ERANGE;
	} else if (!any) {
noconv:
		errno = EINVAL;
	} else if (neg)
		acc = -acc;
	if (endptr != NULL)
		*endptr = (char *)(any ? s - 1 : nptr);
	return (acc);
}
Commit	Line	Data
5b2abdfb	1	/*-
9385eb3d	2	* Copyright (c) 1990, 1993
e9ce8d39 A	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
e9ce8d39 A	13	* 4. Neither the name of the University nor the names of its contributors
	14	* may be used to endorse or promote products derived from this software
	15	* without specific prior written permission.
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	18	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	19	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	20	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	21	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	22	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	23	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	24	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	25	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	26	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	27	* SUCH DAMAGE.
	28	*/
	29
5b2abdfb	30	#if defined(LIBC_SCCS) && !defined(lint)
9385eb3d	31	static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93";
5b2abdfb	32	#endif /* LIBC_SCCS and not lint */
9385eb3d	33	#include <sys/cdefs.h>
1f2f436a	34	__FBSDID("$FreeBSD: src/lib/libc/stdlib/strtol.c,v 1.20 2007/01/09 00:28:10 imp Exp $");
e9ce8d39 A	35
e9ce8d39 A	36	#include <limits.h>
e9ce8d39	37	#include <ctype.h>
9385eb3d	38	#include <errno.h>
e9ce8d39 A	39	#include <stdlib.h>
e9ce8d39 A	40
9385eb3d	41
e9ce8d39	42	/*
9385eb3d	43	* Convert a string to a long integer.
e9ce8d39	44	*
9385eb3d	45	* Assumes that the upper and lower case
e9ce8d39 A	46	* alphabets and digits are each contiguous.
e9ce8d39 A	47	*/
9385eb3d A	48	long
9385eb3d A	49	strtol(const char * __restrict nptr, char ** __restrict endptr, int base)
e9ce8d39	50	{
9385eb3d A	51	const char *s;
	52	unsigned long acc;
	53	char c;
	54	unsigned long cutoff;
	55	int neg, any, cutlim;
e9ce8d39 A	56
	57	/*
	58	* Skip white space and pick up leading +/- sign if any.
	59	* If base is 0, allow 0x for hex and 0 for octal, else
	60	* assume decimal; if base is already 16, allow 0x.
	61	*/
	62	s = nptr;
	63	do {
	64	c = *s++;
9385eb3d	65	} while (isspace((unsigned char)c));
e9ce8d39 A	66	if (c == '-') {
	67	neg = 1;
	68	c = *s++;
	69	} else {
	70	neg = 0;
	71	if (c == '+')
	72	c = *s++;
	73	}
	74	if ((base == 0 \|\| base == 16) &&
1f2f436a A	75	c == '0' && (s == 'x' \|\| s == 'X') &&
	76	((s[1] >= '0' && s[1] <= '9') \|\|
	77	(s[1] >= 'A' && s[1] <= 'F') \|\|
	78	(s[1] >= 'a' && s[1] <= 'f'))) {
e9ce8d39 A	79	c = s[1];
	80	s += 2;
	81	base = 16;
	82	}
	83	if (base == 0)
	84	base = c == '0' ? 8 : 10;
9385eb3d A	85	acc = any = 0;
	86	if (base < 2 \|\| base > 36)
	87	goto noconv;
e9ce8d39 A	88
	89	/*
	90	* Compute the cutoff value between legal numbers and illegal
	91	* numbers. That is the largest legal value, divided by the
	92	* base. An input number that is greater than this value, if
	93	* followed by a legal input character, is too big. One that
	94	* is equal to this value may be valid or not; the limit
	95	* between valid and invalid numbers is then based on the last
9385eb3d A	96	* digit. For instance, if the range for longs is
	97	* [-2147483648..2147483647] and the input base is 10,
	98	* cutoff will be set to 214748364 and cutlim to either
	99	* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
	100	* a value > 214748364, or equal but the next digit is > 7 (or 8),
	101	* the number is too big, and we will return a range error.
e9ce8d39	102	*
9385eb3d	103	* Set 'any' if any `digits' consumed; make it negative to indicate
e9ce8d39 A	104	* overflow.
e9ce8d39 A	105	*/
9385eb3d A	106	cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
	107	: LONG_MAX;
	108	cutlim = cutoff % base;
	109	cutoff /= base;
	110	for ( ; ; c = *s++) {
	111	if (c >= '0' && c <= '9')
e9ce8d39	112	c -= '0';
9385eb3d A	113	else if (c >= 'A' && c <= 'Z')
	114	c -= 'A' - 10;
	115	else if (c >= 'a' && c <= 'z')
	116	c -= 'a' - 10;
e9ce8d39 A	117	else
	118	break;
	119	if (c >= base)
	120	break;
5b2abdfb	121	if (any < 0 \|\| acc > cutoff \|\| (acc == cutoff && c > cutlim))
e9ce8d39 A	122	any = -1;
	123	else {
	124	any = 1;
9385eb3d	125	acc *= base;
e9ce8d39 A	126	acc += c;
	127	}
	128	}
	129	if (any < 0) {
9385eb3d	130	acc = neg ? LONG_MIN : LONG_MAX;
e9ce8d39	131	errno = ERANGE;
9385eb3d A	132	} else if (!any) {
	133	noconv:
	134	errno = EINVAL;
e9ce8d39 A	135	} else if (neg)
e9ce8d39 A	136	acc = -acc;
9385eb3d	137	if (endptr != NULL)
e9ce8d39 A	138	endptr = (char )(any ? s - 1 : nptr);
	139	return (acc);
	140	}