minix/lib/libc/stdio/stdio.c

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/* $NetBSD: stdio.c,v 1.21 2012/03/27 15:05:42 christos 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[] = "@(#)stdio.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: stdio.c,v 1.21 2012/03/27 15:05:42 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include "reentrant.h"
#include "local.h"
/*
* Small standard I/O/seek/close functions.
* These maintain the `known seek offset' for seek optimisation.
*/
ssize_t
__sread(void *cookie, void *buf, size_t n)
{
FILE *fp = cookie;
ssize_t ret;
_DIAGASSERT(cookie != NULL);
_DIAGASSERT(cookie == fp->_cookie);
_DIAGASSERT(buf != NULL);
ret = read(__sfileno(fp), buf, n);
/* if the read succeeded, update the current offset */
if (ret >= 0)
fp->_offset += ret;
else
fp->_flags &= ~__SOFF; /* paranoia */
return ret;
}
ssize_t
__swrite(void *cookie, const void *buf, size_t n)
{
FILE *fp = cookie;
_DIAGASSERT(cookie != NULL);
_DIAGASSERT(cookie == fp->_cookie);
_DIAGASSERT(buf != NULL);
if (fp->_flags & __SAPP)
if (lseek(__sfileno(fp), (off_t)0, SEEK_END) == (off_t)-1)
return -1;
fp->_flags &= ~__SOFF; /* in case FAPPEND mode is set */
return write(__sfileno(fp), buf, n);
}
off_t
__sseek(void *cookie, off_t offset, int whence)
{
FILE *fp = cookie;
off_t ret;
_DIAGASSERT(cookie != NULL);
_DIAGASSERT(cookie == fp->_cookie);
ret = lseek(__sfileno(fp), offset, whence);
if (ret == (off_t)-1L)
fp->_flags &= ~__SOFF;
else {
fp->_flags |= __SOFF;
fp->_offset = ret;
}
return ret;
}
int
__sclose(void *cookie)
{
FILE *fp = cookie;
_DIAGASSERT(cookie != NULL);
_DIAGASSERT(cookie == fp->_cookie);
return close(__sfileno(fp));
}