reset.c

来自「早期freebsd实现」· C语言 代码 · 共 80 行

/*-
 * Copyright (c) 1979, 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.
 * 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.
 */

#ifndef lint
static char sccsid[] = "@(#)RESET.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#include "h00vars.h"

RESET(filep, name, maxnamlen, datasize)

	register struct iorec	*filep;
	char			*name;
	long			maxnamlen;
	long			datasize;
{
	if (name == NULL && filep == INPUT && filep->fname[0] == '\0') {
		if (fseek(filep->fbuf, (long)0, 0) == -1) {
			PERROR("Could not reset ", filep->pfname);
			return;
		}
		filep->funit &= ~EOFF;
		filep->funit |= (SYNC | EOLN);
		return;
	}
	filep = GETNAME(filep, name, maxnamlen, datasize);
	filep->fbuf = fopen(filep->fname, "r");
	if (filep->fbuf == NULL) {
		/*
		 * This allows unnamed temp files to be opened even if
		 * they have not been rewritten yet. We decided to remove
		 * this feature since the standard requires that files be
		 * defined before being reset.
		 *
		if (filep->funit & TEMP) {
			filep->funit |= (EOFF | SYNC | FREAD);
			return;
		}
		 */
		PERROR("Could not open ", filep->pfname);
		return;
	}
	filep->funit |= (SYNC | FREAD);
	if (filep->funit & FTEXT)
		filep->funit |= EOLN;
	if (filep->fblk > PREDEF) {
		setbuf(filep->fbuf, &filep->buf[0]);
	}
}