Int 21 Fn 4301  - Dos 2+ - "chmod" - Set File Attributes                   [D]

   AX = 4301h
   CX = new file attributes (see #1107)
   DS:DX -> ASCIZ filename

Return: CF clear if successful
       AX destroyed
   CF set on error
       AX = error code (01h,02h,03h,05h) (see #1366 at AH=59h)

Notes: will not change volume label or directory attribute bits, but will
     change the other attribute bits of a directory (the directory
     bit must be cleared to successfully change the other attributes of a
     directory, but the directory will not be changed to a normal file as
     a result)
   MS-DOS 4.01 reportedly closes the file if it is currently open
   for security reasons, the Novell NetWare execute-only bit can never
     be cleared; the file must be deleted and recreated
   under the FlashTek X-32 DOS extender, the filename pointer is in DS:EDX
   DOS 5.0 SHARE will close the file if it is currently open in sharing-
     compatibility mode, otherwise a sharing violation critical error is
     generated if the file is currently open
   DR DOS 3.41/5.0 will silently ignore attempts to change the 'directory'
     attribute bit

See Also: AX=4300h,AX=4311h,AX=7143h,INT 2F/AX=110Eh

Bitfields for file attributes:
Bit(s) Description (Table 1107)
 7 shareable (Novell NetWare)
 7 pending deleted files (Novell DOS, OpenDOS)
 6 unused
 5 archive
 4 directory
 3 volume label
   execute-only (Novell NetWare)
 2 system
 1 hidden
 0 read-only