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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)fopen.c 8.1 (Berkeley) 6/4/93"; 35 #endif /* LIBC_SCCS and not lint */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include "namespace.h" 40 #include <sys/types.h> 41 #include <sys/stat.h> 42 #include <fcntl.h> 43 #include <unistd.h> 44 #include <stdio.h> 45 #include <errno.h> 46 #include <limits.h> 47 #include "un-namespace.h" 48 49 #include "local.h" 50 51 FILE * 52 fopen(file, mode) 53 const char * __restrict file; 54 const char * __restrict mode; 55 { 56 FILE *fp; 57 int f; 58 int flags, oflags; 59 60 if ((flags = __sflags(mode, &oflags)) == 0) 61 return (NULL); 62 if ((fp = __sfp()) == NULL) 63 return (NULL); 64 if ((f = _open(file, oflags, DEFFILEMODE)) < 0) { 65 fp->_flags = 0; /* release */ 66 return (NULL); 67 } 68 /* 69 * File descriptors are a full int, but _file is only a short. 70 * If we get a valid file descriptor that is greater than 71 * SHRT_MAX, then the fd will get sign-extended into an 72 * invalid file descriptor. Handle this case by failing the 73 * open. 74 */ 75 if (f > SHRT_MAX) { 76 fp->_flags = 0; /* release */ 77 _close(f); 78 errno = EMFILE; 79 return (NULL); 80 } 81 fp->_file = f; 82 fp->_flags = flags; 83 fp->_cookie = fp; 84 fp->_read = __sread; 85 fp->_write = __swrite; 86 fp->_seek = __sseek; 87 fp->_close = __sclose; 88 /* 89 * When opening in append mode, even though we use O_APPEND, 90 * we need to seek to the end so that ftell() gets the right 91 * answer. If the user then alters the seek pointer, or 92 * the file extends, this will fail, but there is not much 93 * we can do about this. (We could set __SAPP and check in 94 * fseek and ftell.) 95 */ 96 if (oflags & O_APPEND) 97 (void)_sseek(fp, (fpos_t)0, SEEK_END); 98 return (fp); 99 } 100