Format of sharing record:
Offset Size Description )
00h BYTE flag
00h free block
01h allocated block
FFh end marker
01h WORD size of block
03h BYTE checksum of pathname (including NUL)
if sum of ASCII values is N, checksum is (N/256 + N%256)
04h WORD offset in SHARE's DS of first Record Lock Record (see #01638)
06h DWORD pointer to start of system file table chain for file
0Ah WORD unique sequence number
0Ch var ASCIZ full pathname
Note: not supported by DR DOS SHARE 1.1 and 2.0; will reportedly be
supported by Novell DOS 7
SeeAlso: #01636,#01638