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[] = "@(#)setvbuf.c 5.2 (Berkeley) 2/1/91"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include "local.h" 44 45 /* 46 * Set one of the three kinds of buffering, optionally including 47 * a buffer. 48 */ 49 setvbuf(fp, buf, mode, size) 50 register FILE *fp; 51 char *buf; 52 register int mode; 53 register size_t size; 54 { 55 56 /* 57 * Verify arguments. The `int' limit on `size' is due to this 58 * particular implementation. 59 */ 60 if ((mode != _IOFBF && mode != _IOLBF && mode != _IONBF) || 61 (int)size < 0) 62 return (EOF); 63 64 /* 65 * Write current buffer, if any; drop read count, if any. 66 * Make sure putc() will not think fp is line buffered. 67 * Free old buffer if it was from malloc(). Clear line and 68 * non buffer flags, and clear malloc flag. 69 */ 70 (void) __sflush(fp); 71 fp->_r = 0; 72 fp->_lbfsize = 0; 73 if (fp->_flags & __SMBF) 74 free((void *)fp->_bf._base); 75 fp->_flags &= ~(__SLBF|__SNBF|__SMBF); 76 77 /* 78 * Now put back whichever flag is needed, and fix _lbfsize 79 * if line buffered. Ensure output flush on exit if the 80 * stream will be buffered at all. 81 */ 82 switch (mode) { 83 84 case _IONBF: 85 fp->_flags |= __SNBF; 86 fp->_bf._base = fp->_p = fp->_nbuf; 87 fp->_bf._size = 1; 88 break; 89 90 case _IOLBF: 91 fp->_flags |= __SLBF; 92 fp->_lbfsize = -size; 93 /* FALLTHROUGH */ 94 95 case _IOFBF: 96 /* no flag */ 97 __cleanup = _cleanup; 98 fp->_bf._base = fp->_p = (unsigned char *)buf; 99 fp->_bf._size = size; 100 break; 101 } 102 103 /* 104 * Patch up write count if necessary. 105 */ 106 if (fp->_flags & __SWR) 107 fp->_w = fp->_flags & (__SLBF|__SNBF) ? 0 : size; 108 109 return (0); 110 } 111