fopen.c
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上传日期:2007-04-14
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文件大小:3k
- /*-
- * Copyright (c) 1990 The Regents of the University of California.
- * Copyright (c) 1993, 1994 Chris Provenzano.
- * 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.
- */
- #if defined(LIBC_SCCS) && !defined(lint)
- /*static char *sccsid = "from: @(#)fopen.c 5.5 (Berkeley) 2/5/91";*/
- static char *rcsid = "$Id$";
- #endif /* LIBC_SCCS and not lint */
- #include <pthread.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include <stdio.h>
- #include <errno.h>
- #include "local.h"
- extern pthread_mutex_t __sfp_mutex;
- extern pthread_cond_t __sfp_cond;
- extern int __sfp_state;
- FILE *fopen(const char *file, const char *mode)
- {
- register FILE *fp;
- register int f;
- int flags, oflags;
- if ((flags = __sflags(mode, &oflags)) == 0)
- return (NULL);
- if ((f = open(file, oflags, 0666)) < 0) {
- return (NULL);
- }
- __sinit ();
- pthread_mutex_lock(&__sfp_mutex);
- while (__sfp_state) {
- pthread_cond_wait(&__sfp_cond, &__sfp_mutex);
- }
- if (fp = __sfp()) {
- 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, (off_t)0, SEEK_END);
- }
- pthread_mutex_unlock(&__sfp_mutex);
- return (fp);
- }