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<div class="para">\r
<h2>FIL</h2>\r
-<p>The <tt>FIL</tt> structure (file object) holds the state of an open file. It is created by <tt>f_open()</tt> function and discarded by <tt>f_close()</tt> function. Application program must not modify any member in this structure except for <tt>cltbl</tt>. Note that a sector buffer is defined in this structure at non-tiny configuration (<tt>_FS_TINY == 0</tt>), so that the <tt>FIL</tt> structures at that configuration should not be defined as auto variable.</p>\r
+<p>The <tt>FIL</tt> structure (file object) holds the state of an open file. It is created by <tt>f_open</tt> function and discarded by <tt>f_close</tt> function. Application program must not modify any member in this structure except for <tt>cltbl</tt>, or any data on the FAT volume can be collapsed. Note that a sector buffer is defined in this structure at non-tiny configuration (<tt>_FS_TINY == 0</tt>), so that the <tt>FIL</tt> structures at that configuration should not be defined as auto variable.</p>\r
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<pre>\r
<span class="k">typedef</span> <span class="k">struct</span> {\r
- FATFS* fs; <span class="c">/* Pointer to the owner file system object */</span>\r
- WORD id; <span class="c">/* Owner file system mount ID */</span>\r
+ _FDID obj; <span class="c">/* Owner file sytem object and object identifier */</span>\r
BYTE flag; <span class="c">/* File object status flags */</span>\r
BYTE err; <span class="c">/* Abort flag (error code) */</span>\r
- DWORD fptr; <span class="c">/* File read/write pointer (Byte offset origin from top of the file) */</span>\r
- DWORD fsize; <span class="c">/* File size in unit of byte */</span>\r
- DWORD sclust; <span class="c">/* File start cluster */</span>\r
- DWORD clust; <span class="c">/* Current cluster */</span>\r
- DWORD dsect; <span class="c">/* Current data sector */</span>\r
+ FSIZE_t fptr; <span class="c">/* File read/write pointer (Byte offset origin from top of the file) */</span>\r
+ DWORD clust; <span class="c">/* Current cluster of fptr (One cluster behind if fptr is on the cluster boundary. Invalid if fptr == 0.) */</span>\r
+ DWORD sect; <span class="c">/* Current data sector (Can be invalid if fptr is on the cluster boundary.)*/</span>\r
<span class="k">#if</span> !_FS_READONLY\r
- DWORD dir_sect; <span class="c">/* Sector containing the directory entry */</span>\r
+ DWORD dir_sect; <span class="c">/* Sector number containing the directory entry */</span>\r
BYTE* dir_ptr; <span class="c">/* Ponter to the directory entry in the window */</span>\r
<span class="k">#endif</span>\r
<span class="k">#if</span> _USE_FASTSEEK\r
- DWORD* cltbl; <span class="c">/* Pointer to the cluster link map table (Nulled on file open) */</span>\r
-<span class="k">#endif</span>\r
-<span class="k">#if</span> _FS_LOCK\r
- UINT lockid; <span class="c">/* Fle lock ID */</span>\r
+ DWORD* cltbl; <span class="c">/* Pointer to the cluster link map table (Nulled on file open. Set by application.) */</span>\r
<span class="k">#endif</span>\r
<span class="k">#if</span> !_FS_TINY\r
- BYTE buf[_MAX_SS]; <span class="c">/* File private data transfer buffer */</span>\r
+ BYTE buf[_MAX_SS]; <span class="c">/* File private data transfer buffer (Always valid if fptr is not on the sector boundary but can be invalid if fptr is on the sector boundary.) */</span>\r
<span class="k">#endif</span>\r
} FIL;\r
</pre>\r