Int 21 Fn 7160  - Windows95 - Long Filename - "truename" - Canonicalize P  [D]

   AX = 7160h
   CL = 00h
   CH = SUBST expansion flag
       00h return a path containing true path for a SUBSTed drive letter
       80h return a path containing the SUBSTed drive letter
   DS:SI -> ASCIZ filename or path (either long name or short name)
   ES:DI -> 261-byte buffer for canonicalized name

Return: CF set on error
       AX = error code
       02h invalid component in directory path or drive letter only
       03h malformed path or invalid drive letter
       ES:DI buffer unchanged
   CF clear if successful
       ES:DI buffer filled with fully qualified name
       AX destroyed
Desc:  determine the canonical name of the specified filename or path,
     corresponding to the undocumented TRUENAME command in COMMAND.COM

Notes: if a complete path is given, the result will be a short-form complete
     path; otherwise, the given relative path is appended to the
     short-form current directory name, '.'/'..'/'...'/etc. are resolved,
     and the final result uppercased without converting any remaining
     long-form names to short-form
   for compatibility with DOS versions prior to v7.00, the carry flag
     should be set on call to ensure that it is set on exit

See Also: AH=60h,AX=7160h/CL=01h