INT 21,56 - Rename File

AH = 56h

DS:DX = pointer to old ASCIIZ path/filename

ES:DI = pointer to new ASCIIZ path/filename

on return:

AX = error code if CF set (see ~DOS ERROR CODES~)

- supports full pathnames and allows renaming files across

directories and in DOS 3.x allows renaming subdirectories

- does not support use of wildcards unless invoked from via

~INT 21,5D~ in which case error code 12h is returned

- unpredictable result may occur if an opened file is renamed

- see ~Bibliography~ reference to "Undocumented DOS"