Execute the given C<COMMAND> in the same way as command_output_pipe()
does but return both an input pipe filehandle and an output pipe filehandle.
-The function will return return C<($pid, $pipe_in, $pipe_out, $ctx)>.
+The function will return C<($pid, $pipe_in, $pipe_out, $ctx)>.
See C<command_close_bidi_pipe()> for details.
=cut