Int 21 Fn 56  - DOS 2+ - "rename" - Rename File                            [D]

   AH = 56h
   DS:DX -> ASCIZ filename of existing file (no wildcards, but see below)
   ES:DI -> ASCIZ new filename (no wildcards)
   CL = attribute mask (server call only, see below)

Return: CF clear if successful
   CF set on error
       AX = error code (02h,03h,05h,11h) (see AH=59h)

Notes: allows move between directories on same logical volume
   does not set the archive attribute (see AX=4300h), which results in
     incremental backups not backing up the file under its new name
   open files should not be renamed
   (DOS 3+) allows renaming of directories
   (DOS 3.1+) wildcards are allowed if invoked via AX=5D00h, in which case
     error 12h (no more files) is returned on success, and both source and
     destination specs must be canonical (as returned by AH=60h).
     Wildcards in the destination are replaced by the corresponding char
     of each source file being renamed.  Under DOS 3.x, the call will fail
     if the destination wildcard is *.* or equivalent; under DR-DOS 5.0,
     the call will fail if any wildcards are used.  When invoked via
     AX=5D00h, only those files matching the attribute mask in CL are
     renamed.
   under the FlashTek X-32 DOS extender, the old-name pointer is in DS:EDX
     and the new-name pointer is in ES:EDI (DS must equal ES)
BUG:   under DR-DOS 3.41, this function will generate a new directory entry
     with the new name (including any wildcards) which can only be removed
     with a sector editor when invoked via AX=5D00h

See Also: AH=17h,AX=4301h,AH=60h,AX=5D00h