1 /* $OpenBSD: stdio.c,v 1.10 2016/09/21 04:38:56 guenther Exp $ */ 2 /*- 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * Chris Torek. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <stdio.h> 35 #include <unistd.h> 36 #include "local.h" 37 38 /* 39 * Small standard I/O/seek/close functions. 40 * These maintain the `known seek offset' for seek optimisation. 41 */ 42 int 43 __sread(void *cookie, char *buf, int n) 44 { 45 FILE *fp = cookie; 46 int ret; 47 48 ret = read(fp->_file, buf, n); 49 /* if the read succeeded, update the current offset */ 50 if (ret >= 0) 51 fp->_offset += ret; 52 else 53 fp->_flags &= ~__SOFF; /* paranoia */ 54 return (ret); 55 } 56 57 int 58 __swrite(void *cookie, const char *buf, int n) 59 { 60 FILE *fp = cookie; 61 62 if (fp->_flags & __SAPP) 63 (void) lseek(fp->_file, 0, SEEK_END); 64 fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */ 65 return (write(fp->_file, buf, n)); 66 } 67 68 fpos_t 69 __sseek(void *cookie, fpos_t offset, int whence) 70 { 71 FILE *fp = cookie; 72 off_t ret; 73 74 ret = lseek(fp->_file, offset, whence); 75 if (ret == -1) 76 fp->_flags &= ~__SOFF; 77 else { 78 fp->_flags |= __SOFF; 79 fp->_offset = ret; 80 } 81 return (ret); 82 } 83 84 int 85 __sclose(void *cookie) 86 { 87 return (close(((FILE *)cookie)->_file)); 88 } 89