iosync.c

来自「早期freebsd实现」· C语言 代码 · 共 98 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[] = "@(#)IOSYNC.c	8.1 (Berkeley) 6/6/93";
#endif /* not lint */

#include "h00vars.h"

/*
 * insure that a usable image is in the buffer window
 */
IOSYNC(curfile)

	register struct iorec	*curfile;
{
	char			*limit, *ptr;

	if (curfile->funit & FWRITE) {
		ERROR("%s: Attempt to read, but open for writing\n",
			curfile->pfname);
		return;
	}
	if ((curfile->funit & SYNC) == 0) {
		return;
	}
	if (curfile->funit & EOFF) {
		ERROR("%s: Tried to read past end of file\n", curfile->pfname);
		return;
	}
	curfile->funit &= ~SYNC;
	if (curfile->funit & SPEOLN) {
		curfile->funit &= ~(SPEOLN|EOLN);
		curfile->funit |= EOFF;
		return;
	}
	fread(curfile->fileptr, (int)curfile->fsize, 1, curfile->fbuf);
	if (ferror(curfile->fbuf)) {
		ERROR("%s: Tried to read past end of file\n", curfile->pfname);
		return;
	}
	if (feof(curfile->fbuf)) {
		if (curfile->funit & FTEXT) {
			*curfile->fileptr = ' ';
			if (curfile->funit & EOLN) {
				curfile->funit &= ~EOLN;
				curfile->funit |= EOFF;
				return;
			}
			curfile->funit |= (SPEOLN|EOLN);
			return;
		}
		curfile->funit |= EOFF;
		limit = &curfile->fileptr[curfile->fsize];
		for (ptr = curfile->fileptr; ptr < limit; )
			*ptr++ = 0;
		return;
	}
	if (curfile->funit & FTEXT) {
		if (*curfile->fileptr == '\n') {
			curfile->funit |= EOLN;
			*curfile->fileptr = ' ';
			return;
		}
		curfile->funit &= ~EOLN;
	}
}