/* * Copyright (c) 1999 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include "local.h" /* * Allocate a file buffer, or switch to unbuffered I/O. * Per the ANSI C standard, ALL tty devices default to line buffered. * * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek * optimisation) right after the fstat() that finds the buffer size. */ void __smakebuf(fp) register FILE *fp; { register void *p; register int flags; size_t size; int couldbetty; if (fp->_flags & __SNBF) { fp->_bf._base = fp->_p = fp->_nbuf; fp->_bf._size = 1; return; } flags = __swhatbuf(fp, &size, &couldbetty); if ((p = malloc(size)) == NULL) { fp->_flags |= __SNBF; fp->_bf._base = fp->_p = fp->_nbuf; fp->_bf._size = 1; return; } __cleanup = _cleanup; flags |= __SMBF; fp->_bf._base = fp->_p = p; fp->_bf._size = size; if (couldbetty && isatty(fp->_file)) flags |= __SLBF; fp->_flags |= flags; } /* * Internal routine to determine `proper' buffering for a file. */ int __swhatbuf(fp, bufsize, couldbetty) register FILE *fp; size_t *bufsize; int *couldbetty; { struct stat st; if (fp->_file < 0 || fstat(fp->_file, &st) < 0) { *couldbetty = 0; *bufsize = BUFSIZ; return (__SNPT); } /* could be a tty iff it is a character device */ *couldbetty = (st.st_mode & S_IFMT) == S_IFCHR; if (st.st_blksize <= 0) { *bufsize = BUFSIZ; return (__SNPT); } /* * Optimise fseek() only if it is a regular file. (The test for * __sseek is mainly paranoia.) It is safe to set _blksize * unconditionally; it will only be used if __SOPT is also set. */ *bufsize = st.st_blksize; fp->_blksize = st.st_blksize; return ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek ? __SOPT : __SNPT); }