/* $NetBSD: fopen.c,v 1.19 2018/01/17 01:24:30 kamil Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/cdefs.h> #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)fopen.c 8.1 (Berkeley) 6/4/93"; #else __RCSID("$NetBSD: fopen.c,v 1.19 2018/01/17 01:24:30 kamil Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #include <sys/types.h> #include <sys/stat.h> #include <assert.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <errno.h> #include <limits.h> #include "reentrant.h" #include "local.h" FILE * fopen(const char *file, const char *mode) { FILE *fp; int f; int flags, oflags; _DIAGASSERT(file != NULL); if ((flags = __sflags(mode, &oflags)) == 0) return NULL; if ((fp = __sfp()) == NULL) return NULL; if ((f = open(file, oflags, DEFFILEMODE)) < 0) goto release; /* * File descriptors are a full int, but _file is only a short. * If we get a valid file descriptor that is greater or equal to * USHRT_MAX, then the fd will get sign-extended into an * invalid file descriptor. Handle this case by failing the * open. (We treat the short as unsigned, and special-case -1). */ if (f >= USHRT_MAX) { (void)close(f); errno = EMFILE; goto release; } fp->_file = f; fp->_flags = flags; fp->_cookie = fp; fp->_read = __sread; fp->_write = __swrite; fp->_seek = __sseek; fp->_close = __sclose; /* * When opening in append mode, even though we use O_APPEND, * we need to seek to the end so that ftell() gets the right * answer. If the user then alters the seek pointer, or * the file extends, this will fail, but there is not much * we can do about this. (We could set __SAPP and check in * fseek and ftell.) */ if (oflags & O_APPEND) (void) __sseek((void *)fp, (off_t)0, SEEK_END); return fp; release: fp->_flags = 0; /* release */ return NULL; }