47 lines
1.2 KiB
C
47 lines
1.2 KiB
C
/*
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* Copyright (c) 2006-2021, RT-Thread Development Team
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Change Logs:
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* Date Author Notes
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* 2015-01-28 Bernard first version
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*/
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#include <rtthread.h>
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#include <LowLevelIOInterface.h>
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#include <unistd.h>
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#include <compiler_private.h>
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#define DBG_TAG "dlib.syscall.lseek"
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#define DBG_LVL DBG_INFO
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#include <rtdbg.h>
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/*
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* The "__lseek" function makes the next file operation (__read or
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* __write) act on a new location. The parameter "whence" specifies
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* how the "offset" parameter should be interpreted according to the
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* following table:
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*
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* 0 (=SEEK_SET) - Goto location "offset".
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* 1 (=SEEK_CUR) - Go "offset" bytes from the current location.
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* 2 (=SEEK_END) - Go to "offset" bytes from the end.
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*
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* This function should return the current file position, or -1 on
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* failure.
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*/
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#pragma module_name = "?__lseek"
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long __lseek(int handle, long offset, int whence)
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{
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if (handle == _LLIO_STDOUT ||
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handle == _LLIO_STDERR ||
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handle == _LLIO_STDIN)
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return _LLIO_ERROR;
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#ifdef DFS_USING_POSIX
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return lseek(handle, offset, whence);
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#else
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LOG_W(warning_without_fs);
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return _LLIO_ERROR;
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#endif /* DFS_USING_POSIX */
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}
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