This function returns the current file position (in bytes, 0-based) for
This value is typically fed to the seek function at some future time
to get back to the current position.
FILEHANDLE may be an expression whose value gives the name of the
actual filehandle, or a reference to a filehandle object.
FILEHANDLE is omitted, the function returns the
position of the file last read. File positions are only meaningful on
regular files. Devices, pipes, and sockets have no file position.
See seek for an example.