fopen.c (3107B)
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 * 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 rcsid[] = "$OpenBSD: fopen.c,v 1.2 1996/08/19 08:32:41 tholo Exp $"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <fcntl.h> 44 #include <stdio.h> 45 #include <errno.h> 46 #include "local.h" 47 48 FILE * 49 fopen(file, mode) 50 const char *file; 51 const char *mode; 52 { 53 register FILE *fp; 54 register int f; 55 int flags, oflags; 56 57 if ((flags = __sflags(mode, &oflags)) == 0) 58 return (NULL); 59 if ((fp = __sfp()) == NULL) 60 return (NULL); 61 if ((f = open(file, oflags, DEFFILEMODE)) < 0) { 62 fp->_flags = 0; /* release */ 63 return (NULL); 64 } 65 fp->_file = f; 66 fp->_flags = flags; 67 fp->_cookie = fp; 68 fp->_read = __sread; 69 fp->_write = __swrite; 70 fp->_seek = __sseek; 71 fp->_close = __sclose; 72 73 /* 74 * When opening in append mode, even though we use O_APPEND, 75 * we need to seek to the end so that ftell() gets the right 76 * answer. If the user then alters the seek pointer, or 77 * the file extends, this will fail, but there is not much 78 * we can do about this. (We could set __SAPP and check in 79 * fseek and ftell.) 80 */ 81 if (oflags & O_APPEND) 82 (void) __sseek((void *)fp, (fpos_t)0, SEEK_END); 83 return (fp); 84 }