Here is the algorithm for determining the type of output table that will be created when calling tbtcpy: if output == STDOUT then type = text else if extension of output file is .fits (or .fit or .??f) then type = fits else if extension of output file is .qp type = row # but in a qpoe file else if input is text file or STDIN then # text --> text, except for extensions .tab, .fits, .qp if extension of output file is .tab type = row else # .fits & .qp taken care of above type = text end if else type = row end if