stdio.c
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上传日期:2007-04-14
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文件大小:4k
- /*-
- * 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: @(#)stdio.c 5.3 (Berkeley) 2/24/91";*/
- static char *rcsid = "$Id$";
- #endif /* LIBC_SCCS and not lint */
- #include <pthread.h>
- #include <fcntl.h>
- #include <unistd.h>
- #include <stdio.h>
- #include "local.h"
- /*
- * Small standard I/O/seek/close functions.
- * These maintain the `known seek offset' for seek optimisation.
- */
- int __sread(FILE *fp, char *buf, int n)
- {
- register int ret;
-
- /* if the read succeeded, update the current offset */
- if (fd_table[fp->_file]->ops->use_kfds < 2) {
- ret = fd_table[fp->_file]->ops->read(fd_table[fp->_file]->fd,
- fd_table[fp->_file]->flags, buf, n, NULL);
- } else {
- pthread_ssize_t (*readfn)() = fd_table[fp->_file]->ops->read;
- ret = readfn(fd_table[fp->_file]->fd, buf, n);
- }
- if (ret >= 0) {
- fp->_offset += ret;
- } else {
- fp->_flags &= ~__SOFF; /* paranoia */
- }
- return (ret);
- }
- int __swrite(FILE *fp, const char *buf, int n)
- {
- if (fp->_flags & __SAPP)
- (void) lseek(fp->_file, (off_t)0, SEEK_END);
- fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */
- if (fd_table[fp->_file]->ops->use_kfds < 2) {
- return(fd_table[fp->_file]->ops->write(fd_table[fp->_file]->fd,
- fd_table[fp->_file]->flags, buf, n, NULL));
- } else {
- pthread_ssize_t (*writefn)() = fd_table[fp->_file]->ops->write;
- return(writefn(fd_table[fp->_file]->fd,buf,n));
- }
- }
- fpos_t __sseek(FILE *fp, off_t offset, int whence)
- {
- register fpos_t ret;
-
- ret = (fpos_t)lseek(fp->_file, offset, whence);
- if (ret == -1L)
- fp->_flags &= ~__SOFF;
- else {
- fp->_flags |= __SOFF;
- fp->_offset = ret;
- }
- return (ret);
- }
- int __sclose(FILE *fp)
- {
- return (close(fp->_file));
- }