1 /*- 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. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)fflush.c 8.1 (Berkeley) 6/4/93 37 * $FreeBSD: src/lib/libc/stdio/fflush.c,v 1.7 1999/08/28 00:00:58 peter Exp $ 38 * $DragonFly: src/lib/libc/stdio/fflush.c,v 1.4 2004/06/07 20:35:41 hmp Exp $ 39 */ 40 41 #include <errno.h> 42 #include <stdio.h> 43 #include "local.h" 44 #include "libc_private.h" 45 46 /* Flush a single file, or (if fp is NULL) all files. */ 47 int 48 fflush(FILE *fp) 49 { 50 int retval; 51 52 if (fp == NULL) 53 return (_fwalk(__sflush)); 54 FLOCKFILE(fp); 55 if ((fp->_flags & (__SWR | __SRW)) == 0) { 56 errno = EBADF; 57 retval = EOF; 58 } else { 59 retval = __sflush(fp); 60 } 61 FUNLOCKFILE(fp); 62 return (retval); 63 } 64 65 int 66 __sflush(FILE *fp) 67 { 68 unsigned char *p; 69 int n, t; 70 71 t = fp->_flags; 72 if ((t & __SWR) == 0) 73 return (0); 74 75 if ((p = fp->_bf._base) == NULL) 76 return (0); 77 78 n = fp->_p - p; /* write this much */ 79 80 /* 81 * Set these immediately to avoid problems with longjmp and to allow 82 * exchange buffering (via setvbuf) in user write function. 83 */ 84 fp->_p = p; 85 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 86 87 for (; n > 0; n -= t, p += t) { 88 t = (*fp->_write)(fp->_cookie, (char *)p, n); 89 if (t <= 0) { 90 fp->_flags |= __SERR; 91 return (EOF); 92 } 93 } 94 return (0); 95 } 96