rt-thread-official/components/libc/dlib/syscall_open.c

89 lines
2.0 KiB
C

/*
* File : syscall_open.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006 - 2015, RT-Thread Development Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2015-01-28 Bernard first version
*/
#include <rtthread.h>
#include <yfuns.h>
#ifdef RT_USING_DFS
#include <dfs_posix.h>
#endif
#pragma module_name = "?__open"
int __open(const char *filename, int mode)
{
#ifndef RT_USING_DFS
return -1;
#else
int handle;
int open_mode = O_RDONLY;
if (mode & _LLIO_CREAT)
{
open_mode |= O_CREAT;
/* Check what we should do with it if it exists. */
if (mode & _LLIO_APPEND)
{
/* Append to the existing file. */
open_mode |= O_APPEND;
}
if (mode & _LLIO_TRUNC)
{
/* Truncate the existsing file. */
open_mode |= O_TRUNC;
}
}
if (mode & _LLIO_TEXT)
{
/* we didn't support text mode */
}
switch (mode & _LLIO_RDWRMASK)
{
case _LLIO_RDONLY:
break;
case _LLIO_WRONLY:
open_mode |= O_WRONLY;
break;
case _LLIO_RDWR:
/* The file should be opened for both reads and writes. */
open_mode |= O_RDWR;
break;
default:
return -1;
}
handle = open(filename, open_mode, 0);
if (handle < 0)
return -1;
return handle + _LLIO_STDERR + 1;
#endif
}