1 /* $OpenBSD: fopen.c,v 1.10 2019/06/28 13:32:42 deraadt 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 <sys/types.h> 35 #include <sys/stat.h> 36 #include <fcntl.h> 37 #include <limits.h> 38 #include <stdio.h> 39 #include <errno.h> 40 #include <unistd.h> 41 #include "local.h" 42 43 FILE * 44 fopen(const char *file, const char *mode) 45 { 46 FILE *fp; 47 int f; 48 int flags, oflags; 49 50 if ((flags = __sflags(mode, &oflags)) == 0) 51 return (NULL); 52 if ((fp = __sfp()) == NULL) 53 return (NULL); 54 if ((f = open(file, oflags, DEFFILEMODE)) == -1) { 55 fp->_flags = 0; /* release */ 56 return (NULL); 57 } 58 59 /* _file is only a short */ 60 if (f > SHRT_MAX) { 61 fp->_flags = 0; /* release */ 62 close(f); 63 errno = EMFILE; 64 return (NULL); 65 } 66 67 fp->_file = f; 68 fp->_flags = flags; 69 fp->_cookie = fp; 70 fp->_read = __sread; 71 fp->_write = __swrite; 72 fp->_seek = __sseek; 73 fp->_close = __sclose; 74 75 /* 76 * When opening in append mode, even though we use O_APPEND, 77 * we need to seek to the end so that ftell() gets the right 78 * answer. If the user then alters the seek pointer, or 79 * the file extends, this will fail, but there is not much 80 * we can do about this. (We could set __SAPP and check in 81 * fseek and ftell.) 82 */ 83 if (oflags & O_APPEND) 84 (void) __sseek(fp, 0, SEEK_END); 85 return (fp); 86 } 87 DEF_STRONG(fopen); 88