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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char rcsid[] = "$OpenBSD: fflush.c,v 1.3 2003/06/02 20:18:36 millert Exp $"; 35 #endif /* LIBC_SCCS and not lint */ 36 37 #include <errno.h> 38 #include <stdio.h> 39 #include "local.h" 40 41 /* Flush a single file, or (if fp is NULL) all files. */ 42 int 43 fflush(fp) 44 register FILE *fp; 45 { 46 47 if (fp == NULL) 48 return (_fwalk(__sflush)); 49 if ((fp->_flags & (__SWR | __SRW)) == 0) { 50 errno = EBADF; 51 return (EOF); 52 } 53 return (__sflush(fp)); 54 } 55 56 int 57 __sflush(fp) 58 register FILE *fp; 59 { 60 register unsigned char *p; 61 register int n, t; 62 63 t = fp->_flags; 64 if ((t & __SWR) == 0) 65 return (0); 66 67 if ((p = fp->_bf._base) == NULL) 68 return (0); 69 70 n = fp->_p - p; /* write this much */ 71 72 /* 73 * Set these immediately to avoid problems with longjmp and to allow 74 * exchange buffering (via setvbuf) in user write function. 75 */ 76 fp->_p = p; 77 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 78 79 for (; n > 0; n -= t, p += t) { 80 t = (*fp->_write)(fp->_cookie, (char *)p, n); 81 if (t <= 0) { 82 fp->_flags |= __SERR; 83 return (EOF); 84 } 85 } 86 return (0); 87 } 88