/* fgets.c - Read lines of text from a stream. stdio.h *//* Copyright 1992-1993 Wind River Systems, Inc. */ /*modification history--------------------01c,05mar93,jdi  documentation cleanup for 5.1.01b,20sep92,smb  documentation additions01a,29jul92,jcf  Added OBJ_VERIFY	    smb  taken from UCB stdio*/ /*DESCRIPTION * * Copyright (c) 1990 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. * 3. All advertising materials mentioning features or use of this software *    must display the following acknowledgement: *	This product includes software developed by the University of *	California, Berkeley and its contributors. * 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.INCLUDE FILE: stdio.h, string.hSEE ALSO: American National Standard X3.159-1989NOMANUAL*/#include "vxWorks.h"#include "stdio.h"#include "string.h"#include "objLib.h"#include "private/stdioP.h"/******************************************************************************** fgets - read a specified number of characters from a stream (ANSI)** This routine stores in the array <buf> up to <n>-1 characters from a* specified stream.  No additional characters are read after a new-line or* end-of-line.  A null character is written immediately after the last* character read into the array.** If end-of-file is encountered and no characters have been read, the* contents of the array remain unchanged.  If a read error occurs, the array* contents are indeterminate.** INCLUDE FILES: stdio.h ** RETURNS:* A pointer to <buf>, or a null pointer if an error occurs or end-of-file is* encountered and no characters have been read.** SEE ALSO: fread(), fgetc()*/char * fgets    (    char *	buf,	/* where to store characters */    FAST size_t n,	/* no. of bytes to read + 1 */    FAST FILE *	fp	/* stream to read from */    )    {    FAST size_t		len;    FAST char *		s;    FAST uchar_t *      p;    FAST uchar_t *      t;    if (OBJ_VERIFY (fp, fpClassId) != OK)	return (NULL);    if (n < 2)				/* sanity check */	return (NULL);    s = buf;    n--;				/* leave space for NULL */    do 	{	if ((len = fp->_r) <= 0)	/* If the buffer is empty, refill it */	    {	    if (__srefill(fp))		/* EOF/error: partial or no line */		{		if (s == buf)		    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) bcopy ((void *)p, (void *)s, len);	    s[len] = 0;	    return (buf);	    }	fp->_r -= len;	fp->_p += len;	(void) bcopy ((void *)p, (void *)s, len);	s += len;	} while ((n -= len) != 0);    *s = 0;    return (buf);    }