1 /* $NetBSD: fflush.c,v 1.11 1998/02/03 18:41:07 perry Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93"; 43 #else 44 __RCSID("$NetBSD: fflush.c,v 1.11 1998/02/03 18:41:07 perry Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <errno.h> 49 #include <stdio.h> 50 #include "local.h" 51 #include "reentrant.h" 52 53 #ifdef _REENT 54 extern rwlock_t __sfp_lock; 55 #endif 56 57 /* Flush a single file, or (if fp is NULL) all files. */ 58 int 59 fflush(fp) 60 FILE *fp; 61 { 62 int r; 63 64 if (fp == NULL) { 65 rwlock_rdlock(&__sfp_lock); 66 r = _fwalk(__sflush); 67 rwlock_unlock(&__sfp_lock); 68 return r; 69 } 70 71 FLOCKFILE(fp); 72 if ((fp->_flags & (__SWR | __SRW)) == 0) { 73 errno = EBADF; 74 r = EOF; 75 } else { 76 r = __sflush(fp); 77 } 78 FUNLOCKFILE(fp); 79 return r; 80 } 81 82 int 83 __sflush(fp) 84 FILE *fp; 85 { 86 unsigned char *p; 87 int n, t; 88 89 t = fp->_flags; 90 if ((t & __SWR) == 0) 91 return (0); 92 93 if ((p = fp->_bf._base) == NULL) 94 return (0); 95 96 n = fp->_p - p; /* write this much */ 97 98 /* 99 * Set these immediately to avoid problems with longjmp and to allow 100 * exchange buffering (via setvbuf) in user write function. 101 */ 102 fp->_p = p; 103 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 104 105 for (; n > 0; n -= t, p += t) { 106 t = (*fp->_write)(fp->_cookie, (char *)p, n); 107 if (t <= 0) { 108 fp->_flags |= __SERR; 109 return (EOF); 110 } 111 } 112 return (0); 113 } 114