fdopen.c
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上传日期:2007-01-17
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- /* fdopen.c - open file. stdio.h */
- /* Copyright 1992-1993 Wind River Systems, Inc. */
- /*
- modification history
- --------------------
- 01e,05feb99,dgp document errno values
- 01d,07jul93,jmm fixed fdopen to validate the fd (spr 2197)
- 01c,05mar93,jdi documentation cleanup for 5.1.
- 01b,20sep92,smb documentation additions
- 01a,29jul92,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: sys/types.h, fcntl.h, unistd.h, stdio.h, errno.h
- SEE ALSO: American National Standard X3.159-1989
- NOMANUAL
- */
- #include "vxWorks.h"
- #include "stdio.h"
- #include "sys/types.h"
- #include "fcntl.h"
- #include "unistd.h"
- #include "errno.h"
- #include "objLib.h"
- #include "iosLib.h"
- #include "private/stdioP.h"
- /*******************************************************************************
- *
- * fdopen - open a file specified by a file descriptor (POSIX)
- *
- * This routine opens the file specified by the file descriptor <fd> and
- * associates a stream with it.
- * The <mode> argument is used just as in the fopen() function.
- *
- * INCLUDE FILES: stdio.h
- *
- * RETURNS: A pointer to a stream, or a null pointer if an error occurs,
- * with `errno' set to indicate the error.
- *
- * ERRNO: EINVAL
- *
- * SEE ALSO: fopen(), freopen(),
- * .br
- * .I "Information Technology - POSIX - Part 1:"
- * .I "System API [C Language], IEEE Std 1003.1"
- */
- FILE * fdopen
- (
- int fd, /* file descriptor */
- const char * mode /* mode to open with */
- )
- {
- FAST FILE * fp;
- int flags;
- int oflags;
- /* validate the file descriptor */
- if (iosFdValue (fd) == ERROR)
- return (NULL);
-
- if ((flags = __sflags(mode, &oflags)) == 0)
- return (NULL);
- /* Make sure the mode the user wants is a subset of the actual mode. */
- #if FALSE /* XXX */
- if ((fdflags = fcntl(fd, F_GETFL, 0)) < 0)
- return (NULL);
- tmp = fdflags & O_ACCMODE;
- if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE)))
- {
- errno = EINVAL;
- return (NULL);
- }
- #endif
- if ((fp = stdioFpCreate()) == NULL)
- return (NULL);
- fp->_flags = flags;
- /*
- * If opened for appending, but underlying descriptor does not have
- * O_APPEND bit set, assert __SAPP so that __swrite() will lseek to
- * end before each write.
- */
- if ((oflags & O_APPEND) /* XXX && !(fdflags & O_APPEND) */ )
- fp->_flags |= __SAPP;
- fp->_file = fd;
- return (fp);
- }