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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)wbuf.c 8.1 (Berkeley) 6/4/93"; 35#endif /* LIBC_SCCS and not lint */ 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: src/lib/libc/stdio/wbuf.c,v 1.12 2007/01/09 00:28:08 imp Exp $"); 38 39#include <stdio.h> 40#include <errno.h> 41#include "local.h" 42 43/* 44 * Write the given character into the (probably full) buffer for 45 * the given file. Flush the buffer out if it is or becomes full, 46 * or if c=='\n' and the file is line buffered. 47 * 48 * Non-MT-safe 49 */ 50int 51__swbuf(c, fp) 52 int c; 53 FILE *fp; 54{ 55 int n; 56 57 /* 58 * In case we cannot write, or longjmp takes us out early, 59 * make sure _w is 0 (if fully- or un-buffered) or -_bf._size 60 * (if line buffered) so that we will get called again. 61 * If we did not do this, a sufficient number of putc() 62 * calls might wrap _w from negative to positive. 63 */ 64 fp->_w = fp->_lbfsize; 65 if (prepwrite(fp) != 0) { 66 errno = EBADF; 67 return (EOF); 68 } 69 c = (unsigned char)c; 70 71 ORIENT(fp, -1); 72 73 /* 74 * If it is completely full, flush it out. Then, in any case, 75 * stuff c into the buffer. If this causes the buffer to fill 76 * completely, or if c is '\n' and the file is line buffered, 77 * flush it (perhaps a second time). The second flush will always 78 * happen on unbuffered streams, where _bf._size==1; fflush() 79 * guarantees that putc() will always call wbuf() by setting _w 80 * to 0, so we need not do anything else. 81 */ 82 n = fp->_p - fp->_bf._base; 83 if (n >= fp->_bf._size) { 84 if (__fflush(fp)) 85 return (EOF); 86 n = 0; 87 } 88 fp->_w--; 89 *fp->_p++ = c; 90 if (++n == fp->_bf._size || (fp->_flags & __SLBF && c == '\n')) 91 if (__fflush(fp)) 92 return (EOF); 93 return (c); 94} 95