11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1990, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This code is derived from software contributed to Berkeley by 61573Srgrimes * Chris Torek. 71573Srgrimes * 81573Srgrimes * Redistribution and use in source and binary forms, with or without 91573Srgrimes * modification, are permitted provided that the following conditions 101573Srgrimes * are met: 111573Srgrimes * 1. Redistributions of source code must retain the above copyright 121573Srgrimes * notice, this list of conditions and the following disclaimer. 131573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141573Srgrimes * notice, this list of conditions and the following disclaimer in the 151573Srgrimes * documentation and/or other materials provided with the distribution. 16249808Semaste * 3. Neither the name of the University nor the names of its contributors 171573Srgrimes * may be used to endorse or promote products derived from this software 181573Srgrimes * without specific prior written permission. 191573Srgrimes * 201573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 211573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 221573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 231573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 241573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 251573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 261573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 271573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 281573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 291573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 301573Srgrimes * SUCH DAMAGE. 311573Srgrimes */ 321573Srgrimes 331573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 341573Srgrimesstatic char sccsid[] = "@(#)setvbuf.c 8.2 (Berkeley) 11/16/93"; 351573Srgrimes#endif /* LIBC_SCCS and not lint */ 3692986Sobrien#include <sys/cdefs.h> 3792986Sobrien__FBSDID("$FreeBSD: stable/10/lib/libc/stdio/setvbuf.c 321074 2017-07-17 14:09:34Z kib $"); 381573Srgrimes 3971579Sdeischen#include "namespace.h" 401573Srgrimes#include <stdio.h> 411573Srgrimes#include <stdlib.h> 4271579Sdeischen#include "un-namespace.h" 431573Srgrimes#include "local.h" 4435129Sjb#include "libc_private.h" 451573Srgrimes 461573Srgrimes/* 471573Srgrimes * Set one of the three kinds of buffering, optionally including 481573Srgrimes * a buffer. 491573Srgrimes */ 5013545Sjulianint 51103012Stjrsetvbuf(FILE * __restrict fp, char * __restrict buf, int mode, size_t size) 521573Srgrimes{ 5392889Sobrien int ret, flags; 541573Srgrimes size_t iosize; 551573Srgrimes int ttyflag; 561573Srgrimes 571573Srgrimes /* 581573Srgrimes * Verify arguments. The `int' limit on `size' is due to this 591573Srgrimes * particular implementation. Note, buf and size are ignored 601573Srgrimes * when setting _IONBF. 611573Srgrimes */ 621573Srgrimes if (mode != _IONBF) 631573Srgrimes if ((mode != _IOFBF && mode != _IOLBF) || (int)size < 0) 641573Srgrimes return (EOF); 651573Srgrimes 66321074Skib FLOCKFILE_CANCELSAFE(fp); 671573Srgrimes /* 681573Srgrimes * Write current buffer, if any. Discard unread input (including 691573Srgrimes * ungetc data), cancel line buffering, and free old buffer if 701573Srgrimes * malloc()ed. We also clear any eof condition, as if this were 711573Srgrimes * a seek. 721573Srgrimes */ 731573Srgrimes ret = 0; 741573Srgrimes (void)__sflush(fp); 751573Srgrimes if (HASUB(fp)) 761573Srgrimes FREEUB(fp); 771573Srgrimes fp->_r = fp->_lbfsize = 0; 781573Srgrimes flags = fp->_flags; 791573Srgrimes if (flags & __SMBF) 801573Srgrimes free((void *)fp->_bf._base); 8182839Sache flags &= ~(__SLBF | __SNBF | __SMBF | __SOPT | __SOFF | __SNPT | __SEOF); 821573Srgrimes 831573Srgrimes /* If setting unbuffered mode, skip all the hard work. */ 841573Srgrimes if (mode == _IONBF) 851573Srgrimes goto nbf; 861573Srgrimes 871573Srgrimes /* 881573Srgrimes * Find optimal I/O size for seek optimization. This also returns 891573Srgrimes * a `tty flag' to suggest that we check isatty(fd), but we do not 901573Srgrimes * care since our caller told us how to buffer. 911573Srgrimes */ 921573Srgrimes flags |= __swhatbuf(fp, &iosize, &ttyflag); 931573Srgrimes if (size == 0) { 941573Srgrimes buf = NULL; /* force local allocation */ 951573Srgrimes size = iosize; 961573Srgrimes } 971573Srgrimes 981573Srgrimes /* Allocate buffer if needed. */ 991573Srgrimes if (buf == NULL) { 1001573Srgrimes if ((buf = malloc(size)) == NULL) { 1011573Srgrimes /* 1021573Srgrimes * Unable to honor user's request. We will return 1031573Srgrimes * failure, but try again with file system size. 1041573Srgrimes */ 1051573Srgrimes ret = EOF; 1061573Srgrimes if (size != iosize) { 1071573Srgrimes size = iosize; 1081573Srgrimes buf = malloc(size); 1091573Srgrimes } 1101573Srgrimes } 1111573Srgrimes if (buf == NULL) { 1121573Srgrimes /* No luck; switch to unbuffered I/O. */ 1131573Srgrimesnbf: 1141573Srgrimes fp->_flags = flags | __SNBF; 1151573Srgrimes fp->_w = 0; 1161573Srgrimes fp->_bf._base = fp->_p = fp->_nbuf; 1171573Srgrimes fp->_bf._size = 1; 118321074Skib goto end; 1191573Srgrimes } 1201573Srgrimes flags |= __SMBF; 1211573Srgrimes } 1221573Srgrimes 1231573Srgrimes /* 1241573Srgrimes * Kill any seek optimization if the buffer is not the 1251573Srgrimes * right size. 1261573Srgrimes * 1271573Srgrimes * SHOULD WE ALLOW MULTIPLES HERE (i.e., ok iff (size % iosize) == 0)? 1281573Srgrimes */ 1291573Srgrimes if (size != iosize) 1301573Srgrimes flags |= __SNPT; 1311573Srgrimes 1321573Srgrimes /* 1331573Srgrimes * Fix up the FILE fields, and set __cleanup for output flush on 1341573Srgrimes * exit (since we are buffered in some way). 1351573Srgrimes */ 1361573Srgrimes if (mode == _IOLBF) 1371573Srgrimes flags |= __SLBF; 1381573Srgrimes fp->_flags = flags; 1391573Srgrimes fp->_bf._base = fp->_p = (unsigned char *)buf; 1401573Srgrimes fp->_bf._size = size; 1411573Srgrimes /* fp->_lbfsize is still 0 */ 1421573Srgrimes if (flags & __SWR) { 1431573Srgrimes /* 1441573Srgrimes * Begin or continue writing: see __swsetup(). Note 1451573Srgrimes * that __SNBF is impossible (it was handled earlier). 1461573Srgrimes */ 1471573Srgrimes if (flags & __SLBF) { 1481573Srgrimes fp->_w = 0; 1491573Srgrimes fp->_lbfsize = -fp->_bf._size; 1501573Srgrimes } else 1511573Srgrimes fp->_w = size; 1521573Srgrimes } else { 1531573Srgrimes /* begin/continue reading, or stay in intermediate state */ 1541573Srgrimes fp->_w = 0; 1551573Srgrimes } 1561573Srgrimes __cleanup = _cleanup; 1571573Srgrimes 158321074Skibend: 159321074Skib FUNLOCKFILE_CANCELSAFE(); 1601573Srgrimes return (ret); 1611573Srgrimes} 162