1 /* $OpenBSD: fflush.c,v 1.5 2005/08/08 08:05:36 espie Exp $ */ 2 /*- 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Chris Torek. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <errno.h> 35 #include <stdio.h> 36 #include "local.h" 37 38 /* Flush a single file, or (if fp is NULL) all files. */ 39 int 40 fflush(FILE *fp) 41 { 42 43 if (fp == NULL) 44 return (_fwalk(__sflush)); 45 if ((fp->_flags & (__SWR | __SRW)) == 0) { 46 errno = EBADF; 47 return (EOF); 48 } 49 return (__sflush(fp)); 50 } 51 52 int 53 __sflush(FILE *fp) 54 { 55 unsigned char *p; 56 int n, t; 57 58 t = fp->_flags; 59 if ((t & __SWR) == 0) 60 return (0); 61 62 if ((p = fp->_bf._base) == NULL) 63 return (0); 64 65 n = fp->_p - p; /* write this much */ 66 67 /* 68 * Set these immediately to avoid problems with longjmp and to allow 69 * exchange buffering (via setvbuf) in user write function. 70 */ 71 fp->_p = p; 72 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 73 74 for (; n > 0; n -= t, p += t) { 75 t = (*fp->_write)(fp->_cookie, (char *)p, n); 76 if (t <= 0) { 77 fp->_flags |= __SERR; 78 return (EOF); 79 } 80 } 81 return (0); 82 } 83
