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. 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[] = "@(#)fflush.c 8.1 (Berkeley) 6/4/93"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <errno.h> 42 #include <stdio.h> 43 #include "local.h" 44 45 /* Flush a single file, or (if fp is NULL) all files. */ 46 fflush(fp) 47 register FILE *fp; 48 { 49 50 if (fp == NULL) 51 return (_fwalk(__sflush)); 52 if ((fp->_flags & (__SWR | __SRW)) == 0) { 53 errno = EBADF; 54 return (EOF); 55 } 56 return (__sflush(fp)); 57 } 58 59 __sflush(fp) 60 register FILE *fp; 61 { 62 register unsigned char *p; 63 register int n, t; 64 65 t = fp->_flags; 66 if ((t & __SWR) == 0) 67 return (0); 68 69 if ((p = fp->_bf._base) == NULL) 70 return (0); 71 72 n = fp->_p - p; /* write this much */ 73 74 /* 75 * Set these immediately to avoid problems with longjmp and to allow 76 * exchange buffering (via setvbuf) in user write function. 77 */ 78 fp->_p = p; 79 fp->_w = t & (__SLBF|__SNBF) ? 0 : fp->_bf._size; 80 81 for (; n > 0; n -= t, p += t) { 82 t = (*fp->_write)(fp->_cookie, (char *)p, n); 83 if (t <= 0) { 84 fp->_flags |= __SERR; 85 return (EOF); 86 } 87 } 88 return (0); 89 } 90