1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * 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 37 #if defined(LIBC_SCCS) && !defined(lint) 38 /*static char *sccsid = "from: @(#)fflush.c 5.1 (Berkeley) 1/20/91";*/ 39 static char *rcsid = "$Id: fflush.c,v 1.5 1993/08/26 00:46:39 jtc Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/errno.h> 43 #include <stdio.h> 44 #include "local.h" 45 46 /* Flush a single file, or (if fp is NULL) all files. */ 47 fflush(fp) 48 register FILE *fp; 49 { 50 if (fp == NULL) 51 return (_fwalk(__sflush)); 52 53 if ((fp->_flags & (__SWR | __SRW)) == 0) { 54 errno = EBADF; 55 return (EOF); 56 } 57 return (__sflush(fp)); 58 } 59 60 __sflush(fp) 61 register FILE *fp; 62 { 63 register unsigned char *p; 64 register int n, t; 65 66 t = fp->_flags; 67 if ((t & __SWR) == 0) 68 return (0); 69 70 if ((p = fp->_bf._base) == NULL) 71 return (0); 72 73 n = fp->_p - p; /* write this much */ 74 75 /* 76 * Set these immediately to avoid problems with longjmp and to allow 77 * exchange buffering (via setvbuf) in user write function. 78 */ 79 fp->_p = p; 80 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 81 82 for (; n > 0; n -= t, p += t) { 83 t = (*fp->_write)(fp->_cookie, (char *)p, n); 84 if (t <= 0) { 85 fp->_flags |= __SERR; 86 return (EOF); 87 } 88 } 89 return (0); 90 } 91