11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* $OpenBSD: makebuf.c,v 1.8 2005/12/28 18:50:22 millert Exp $ */ 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/*- 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (c) 1990, 1993 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * The Regents of the University of California. All rights reserved. 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * This code is derived from software contributed to Berkeley by 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Chris Torek. 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 1. Redistributions of source code must retain the above copyright 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 2. Redistributions in binary form must reproduce the above copyright 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer in the 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * documentation and/or other materials provided with the distribution. 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 3. Neither the name of the University nor the names of its contributors 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * may be used to endorse or promote products derived from this software 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * without specific prior written permission. 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SUCH DAMAGE. 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <sys/types.h> 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <sys/stat.h> 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <unistd.h> 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdio.h> 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdlib.h> 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "local.h" 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Allocate a file buffer, or switch to unbuffered I/O. 431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Per the ANSI C standard, ALL tty devices default to line buffered. 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * optimisation) right after the fstat() that finds the buffer size. 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectvoid 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project__smakebuf(FILE *fp) 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project void *p; 521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int flags; 531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size_t size; 541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int couldbetty; 551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_flags & __SNBF) { 571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._base = fp->_p = fp->_nbuf; 581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._size = 1; 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return; 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags = __swhatbuf(fp, &size, &couldbetty); 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((p = malloc(size)) == NULL) { 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags |= __SNBF; 641dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._base = fp->_p = fp->_nbuf; 651dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._size = 1; 661dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return; 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project __atexit_register_cleanup(_cleanup); 691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags |= __SMBF; 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._base = fp->_p = p; 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._size = size; 721dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (couldbetty && isatty(fp->_file)) 731dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags |= __SLBF; 741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags |= flags; 751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Internal routine to determine `proper' buffering for a file. 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectint 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project__swhatbuf(FILE *fp, size_t *bufsize, int *couldbetty) 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project struct stat st; 841dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_file < 0 || fstat(fp->_file, &st) < 0) { 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project *couldbetty = 0; 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project *bufsize = BUFSIZ; 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (__SNPT); 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* could be a tty iff it is a character device */ 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project *couldbetty = S_ISCHR(st.st_mode); 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (st.st_blksize == 0) { 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project *bufsize = BUFSIZ; 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (__SNPT); 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Optimise fseek() only if it is a regular file. (The test for 1001dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * __sseek is mainly paranoia.) It is safe to set _blksize 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * unconditionally; it will only be used if __SOPT is also set. 1021dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1031dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project *bufsize = st.st_blksize; 1041dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_blksize = st.st_blksize; 1051dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return ((st.st_mode & S_IFMT) == S_IFREG && fp->_seek == __sseek ? 1061dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project __SOPT : __SNPT); 1071dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 108