/* fopen.c - open a file. stdio.h */ /* Copyright 1992-1995 Wind River Systems, Inc. */ /* modification history -------------------- 01d,10feb95,jdi doc format tweak. 01c,05mar93,jdi documentation cleanup for 5.1. 01b,20sep92,smb documentation additions 01a,29jul92,jcf modified to use stdioFpCreate and close memory leaks. smb taken from UCB stdio. */ /* DESCRIPTION * Copyright (c) 1990 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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 FILE: stdio.h, error.h SEE ALSO: American National Standard X3.159-1989 NOMANUAL */ #include "vxWorks.h" #include "stdio.h" #include "sys/types.h" #include "sys/stat.h" #include "ioLib.h" #include "fcntl.h" #include "errno.h" #include "private/stdioP.h" /****************************************************************************** * * fopen - open a file specified by name (ANSI) * * This routine opens a file whose name is the string pointed to by * and associates a stream with it. * The argument points to a string beginning with one of the following * sequences: * .iP r "" 3 * open text file for reading * .iP w * truncate to zero length or create text file for writing * .iP a * append; open or create text file for writing at end-of-file * .iP rb * open binary file for reading * .iP wb * truncate to zero length or create binary file for writing * .iP ab * append; open or create binary file for writing at end-of-file * .iP r+ * open text file for update (reading and writing) * .iP w+ * truncate to zero length or create text file for update. * .iP a+ * append; open or create text file for update, writing at end-of-file * .iP "r+b / rb+" * open binary file for update (reading and writing) * .iP "w+b / wb+" * truncate to zero length or create binary file for update * .iP "a+b / ab+" * append; open or create binary file for update, writing at end-of-file * .LP * * Opening a file with read mode (`r' as the first character in the * argument) fails if the file does not exist or cannot be read. * * Opening a file with append mode (`a' as the first character in the * argument) causes all subsequent writes to the file to be forced to the * then current end-of-file, regardless of intervening calls to fseek(). In * some implementations, opening a binary file with append mode (`b' as the * second or third character in the argument) may initially position * the file position indicator for the stream beyond the last data written, * because of null character padding. In VxWorks, whether append mode is * supported is device-specific. * * When a file is opened with update mode (`+' as the second or third * character in the argument), both input and output may be performed * on the associated stream. However, output may not be directly followed by * input without an intervening call to fflush() or to a file positioning * function (fseek(), fsetpos(), or rewind()), and input may not be directly * followed by output without an intervening call to a file positioning * function, unless the input operation encounters end-of-file. Opening (or * creating) a text file with update mode may instead open (or create) a * binary stream in some implementations. * * When opened, a stream is fully buffered if and only if it can be determined * not to refer to an interactive device. The error and end-of-file * indicators for the stream are cleared. * * INCLUDE FILES: stdio.h * * RETURNS: * A pointer to the object controlling the stream, or a null pointer if the * operation fails. * * SEE ALSO: fdopen(), freopen() */ FILE * fopen ( const char * file, /* name of file */ const char * mode /* mode */ ) { FAST FILE * fp; FAST int f; int flags; int oflags; if ((flags = __sflags (mode, &oflags)) == 0) return (NULL); if ((fp = stdioFpCreate ()) == NULL) return (NULL); if ((f = open (file, oflags, DEFFILEMODE )) < 0) { fp->_flags = 0x0; /* release */ stdioFpDestroy (fp); /* destroy file pointer */ return (NULL); } fp->_file = f; fp->_flags = flags; /* * 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, (fpos_t)0, SEEK_END); return (fp); }
