[apple/libc.git] / stdio / FreeBSD / fgets.c

/*-
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * 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[] = "@(#)fgets.c	8.2 (Berkeley) 12/22/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdio/fgets.c,v 1.14 2007/01/09 00:28:06 imp Exp $");

#include "namespace.h"
#include <stdio.h>
#include <string.h>
#include "un-namespace.h"
#include "local.h"
#include "libc_private.h"

/*
 * Read at most n-1 characters from the given file.
 * Stop when a newline has been read, or the count runs out.
 * Return first argument, or NULL if no characters were read.
 */
char *
fgets(buf, n, fp)
	char *buf;
	int n;
	FILE *fp;
{
	size_t len;
	char *s;
	unsigned char *p, *t;

	if (n <= 0)		/* sanity check */
		return (NULL);

	FLOCKFILE(fp);
	ORIENT(fp, -1);
	s = buf;
	n--;			/* leave space for NUL */
	while (n != 0) {
		/*
		 * If the buffer is empty, refill it.
		 */
		if ((len = fp->_r) <= 0) {
			if (__srefill(fp)) {
				/* EOF/error: stop with partial or no line */
				if (s == buf) {
					FUNLOCKFILE(fp);
					return (NULL);
				}
				break;
			}
			len = fp->_r;
		}
		p = fp->_p;

		/*
		 * Scan through at most n bytes of the current buffer,
		 * looking for '\n'.  If found, copy up to and including
		 * newline, and stop.  Otherwise, copy entire chunk
		 * and loop.
		 */
		if (len > n)
			len = n;
		t = memchr((void *)p, '\n', len);
		if (t != NULL) {
			len = ++t - p;
			fp->_r -= len;
			fp->_p = t;
			(void)memcpy((void *)s, (void *)p, len);
			s[len] = 0;
			FUNLOCKFILE(fp);
			return (buf);
		}
		fp->_r -= len;
		fp->_p += len;
		(void)memcpy((void *)s, (void *)p, len);
		s += len;
		n -= len;
	}
	*s = 0;
	FUNLOCKFILE(fp);
	return (buf);
}
Commit	Line	Data
9385eb3d	1	/*-
e9ce8d39 A	2	* Copyright (c) 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Chris Torek.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
e9ce8d39 A	16	* 4. Neither the name of the University nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*/
	32
9385eb3d A	33	#if defined(LIBC_SCCS) && !defined(lint)
	34	static char sccsid[] = "@(#)fgets.c 8.2 (Berkeley) 12/22/93";
	35	#endif /* LIBC_SCCS and not lint */
	36	#include <sys/cdefs.h>
1f2f436a	37	__FBSDID("$FreeBSD: src/lib/libc/stdio/fgets.c,v 1.14 2007/01/09 00:28:06 imp Exp $");
e9ce8d39	38
9385eb3d	39	#include "namespace.h"
e9ce8d39 A	40	#include <stdio.h>
e9ce8d39 A	41	#include <string.h>
9385eb3d A	42	#include "un-namespace.h"
	43	#include "local.h"
	44	#include "libc_private.h"
e9ce8d39 A	45
	46	/*
	47	* Read at most n-1 characters from the given file.
	48	* Stop when a newline has been read, or the count runs out.
	49	* Return first argument, or NULL if no characters were read.
	50	*/
	51	char *
	52	fgets(buf, n, fp)
	53	char *buf;
9385eb3d A	54	int n;
9385eb3d A	55	FILE *fp;
e9ce8d39	56	{
9385eb3d A	57	size_t len;
	58	char *s;
	59	unsigned char p, t;
e9ce8d39	60
9385eb3d	61	if (n <= 0) /* sanity check */
e9ce8d39 A	62	return (NULL);
e9ce8d39 A	63
9385eb3d A	64	FLOCKFILE(fp);
9385eb3d A	65	ORIENT(fp, -1);
e9ce8d39 A	66	s = buf;
	67	n--; /* leave space for NUL */
	68	while (n != 0) {
	69	/*
	70	* If the buffer is empty, refill it.
	71	*/
	72	if ((len = fp->_r) <= 0) {
	73	if (__srefill(fp)) {
	74	/* EOF/error: stop with partial or no line */
9385eb3d A	75	if (s == buf) {
9385eb3d A	76	FUNLOCKFILE(fp);
e9ce8d39	77	return (NULL);
9385eb3d	78	}
e9ce8d39 A	79	break;
	80	}
	81	len = fp->_r;
	82	}
	83	p = fp->_p;
	84
	85	/*
	86	* Scan through at most n bytes of the current buffer,
	87	* looking for '\n'. If found, copy up to and including
	88	* newline, and stop. Otherwise, copy entire chunk
	89	* and loop.
	90	*/
	91	if (len > n)
	92	len = n;
	93	t = memchr((void *)p, '\n', len);
	94	if (t != NULL) {
	95	len = ++t - p;
	96	fp->_r -= len;
	97	fp->_p = t;
	98	(void)memcpy((void )s, (void )p, len);
	99	s[len] = 0;
9385eb3d	100	FUNLOCKFILE(fp);
e9ce8d39 A	101	return (buf);
	102	}
	103	fp->_r -= len;
	104	fp->_p += len;
	105	(void)memcpy((void )s, (void )p, len);
	106	s += len;
	107	n -= len;
	108	}
	109	*s = 0;
9385eb3d	110	FUNLOCKFILE(fp);
e9ce8d39 A	111	return (buf);
e9ce8d39 A	112	}