Date: Sat, 15 Nov 1997 09:49:01 -0500 (EST)
Message-Id: <199711151449.JAA01185@delorie.com>
To: DJGPP mailing list <djgpp AT delorie DOT com>
From: Alexander Bokovoy <bokovoy AT bspu DOT ac DOT by>
Subject: Write LFN handler for raw DOS?
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Hi, All
Is anybody can do the following thing:
 Write handler for file I/O operations (in libc, if I correct) that use
 FCB-interface for getting/putting long file names under raw DOS on
FAT32 drives? If I correct, this is relative simple work.
It would be very useful because then Windows'95 is no needed for
operating with LFN. Norton Disk Editor for Windows 95 (which is DOS32 application)
have this interface so long file names can be viewed in raw DOS.

 Here is an extraction from Ralf Brown's IntList 5.4: (interrup.e)

Format of DOS directory entry:
Offset  Size    Description     (Table 1007)
 00h  8 BYTEs   blank-padded filename
 08h  3 BYTEs   blank-padded file extension
 0Bh    BYTE    attributes
 0Ch 10 BYTEs   (MS-DOS 1.0-6.22) reserved
                (DR-DOS) used to store file password
                (MS-DOS 7/Windows95) additional file times (see #1008)
 16h    WORD    time of creation or last update (see #1317 at AX=5700h)
 18h    WORD    date of creation or last update (see #1318 at AX=5700h)
 1Ah    WORD    starting cluster number (see also AX=440Dh/CX=0871h)
 1Ch    DWORD   file size
SeeAlso: #1009,#2276,#2277

Format of MS-DOS 7/Windows95 additional file times:
Offset  Size    Description     (Table 1008)
 00h    BYTE    reserved
 01h    BYTE    10-millisecond units past creation time below
 02h    WORD    file creation time
 04h    WORD    file creation date
 06h    WORD    last-access date
 08h    WORD    (FAT32) high word of starting cluster number
Note:   this data is stored beginning at offset 0Ch in a standard directory
          entry
SeeAlso: #1007

Format of MS-DOS 7/Windows95 long-filename directory entry:
Offset  Size    Description     (Table 1009)
 00h    BYTE    LFN record sequence (bit 6 set if last record for file)
 01h 10 BYTEs   long filename, first part
 0Bh    BYTE    0Fh (otherwise impossible file attribute, used as signature)
 0Ch    BYTE    reserved??? (00h)
 0Dh    BYTE    checksum for short filename
 10h 10 BYTEs   long filename, second part
 1Ah    WORD    first cluster number (always 0000h for LFN records)
 1Ch  4 BYTEs   long filename, third part
Notes:  long-filename entries are always stored in the directory just prior
          to the short-name entry for a file
        multiple LFN records are used if the long filename does not fit into
          a single record
        the short-filename checksum byte is computed by adding up the
          eleven bytes of the short filename, rotating the intermediate
          sum right one bit before adding the next character
        the long filename is encoded as 16-bit Unicode characters; for most
          filenames, this appears in the directory as the ASCII character
          followed by 00h
SeeAlso: #1007



Alexander Bokovoy, <bokovoy AT bspu DOT ac DOT by>
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