1 /* $OpenBSD: fflush.c,v 1.9 2015/08/31 02:53:57 guenther 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 int r; 43 44 if (fp == NULL) 45 return (_fwalk(__sflush_locked)); 46 FLOCKFILE(fp); 47 if ((fp->_flags & (__SWR | __SRW)) == 0) { 48 errno = EBADF; 49 r = EOF; 50 } else 51 r = __sflush(fp); 52 FUNLOCKFILE(fp); 53 return (r); 54 } 55 DEF_STRONG(fflush); 56 57 int 58 __sflush(FILE *fp) 59 { 60 unsigned char *p; 61 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 89 int 90 __sflush_locked(FILE *fp) 91 { 92 int r; 93 94 FLOCKFILE(fp); 95 r = __sflush(fp); 96 FUNLOCKFILE(fp); 97 return (r); 98 } 99