fflush.c revision 35129
11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1990, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This code is derived from software contributed to Berkeley by 61573Srgrimes * Chris Torek. 71573Srgrimes * 81573Srgrimes * Redistribution and use in source and binary forms, with or without 91573Srgrimes * modification, are permitted provided that the following conditions 101573Srgrimes * are met: 111573Srgrimes * 1. Redistributions of source code must retain the above copyright 121573Srgrimes * notice, this list of conditions and the following disclaimer. 131573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141573Srgrimes * notice, this list of conditions and the following disclaimer in the 151573Srgrimes * documentation and/or other materials provided with the distribution. 161573Srgrimes * 3. All advertising materials mentioning features or use of this software 171573Srgrimes * must display the following acknowledgement: 181573Srgrimes * This product includes software developed by the University of 191573Srgrimes * California, Berkeley and its contributors. 201573Srgrimes * 4. Neither the name of the University nor the names of its contributors 211573Srgrimes * may be used to endorse or promote products derived from this software 221573Srgrimes * without specific prior written permission. 231573Srgrimes * 241573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341573Srgrimes * SUCH DAMAGE. 351573Srgrimes */ 361573Srgrimes 371573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 3816586Sjraynard#if 0 391573Srgrimesstatic char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93"; 4016586Sjraynard#endif 4116586Sjraynardstatic const char rcsid[] = 4235129Sjb "$Id: fflush.c,v 1.5 1997/02/22 15:01:50 peter Exp $"; 431573Srgrimes#endif /* LIBC_SCCS and not lint */ 441573Srgrimes 451573Srgrimes#include <errno.h> 461573Srgrimes#include <stdio.h> 471573Srgrimes#include "local.h" 4835129Sjb#include "libc_private.h" 491573Srgrimes 501573Srgrimes/* Flush a single file, or (if fp is NULL) all files. */ 5113545Sjulianint 521573Srgrimesfflush(fp) 531573Srgrimes register FILE *fp; 541573Srgrimes{ 5513545Sjulian int retval; 561573Srgrimes 571573Srgrimes if (fp == NULL) 581573Srgrimes return (_fwalk(__sflush)); 5935129Sjb FLOCKFILE(fp); 601573Srgrimes if ((fp->_flags & (__SWR | __SRW)) == 0) { 611573Srgrimes errno = EBADF; 6213545Sjulian retval = EOF; 6313545Sjulian } else { 6413545Sjulian retval = __sflush(fp); 651573Srgrimes } 6635129Sjb FUNLOCKFILE(fp); 6713545Sjulian return (retval); 681573Srgrimes} 691573Srgrimes 7013545Sjulianint 711573Srgrimes__sflush(fp) 721573Srgrimes register FILE *fp; 731573Srgrimes{ 741573Srgrimes register unsigned char *p; 751573Srgrimes register int n, t; 761573Srgrimes 771573Srgrimes t = fp->_flags; 781573Srgrimes if ((t & __SWR) == 0) 791573Srgrimes return (0); 801573Srgrimes 811573Srgrimes if ((p = fp->_bf._base) == NULL) 821573Srgrimes return (0); 831573Srgrimes 841573Srgrimes n = fp->_p - p; /* write this much */ 851573Srgrimes 861573Srgrimes /* 871573Srgrimes * Set these immediately to avoid problems with longjmp and to allow 881573Srgrimes * exchange buffering (via setvbuf) in user write function. 891573Srgrimes */ 901573Srgrimes fp->_p = p; 911573Srgrimes fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 921573Srgrimes 931573Srgrimes for (; n > 0; n -= t, p += t) { 941573Srgrimes t = (*fp->_write)(fp->_cookie, (char *)p, n); 951573Srgrimes if (t <= 0) { 961573Srgrimes fp->_flags |= __SERR; 971573Srgrimes return (EOF); 981573Srgrimes } 991573Srgrimes } 1001573Srgrimes return (0); 1011573Srgrimes} 102