The command interpreter and command language design of the com-share COMMANDER II system

The command language of the COMMANDER II time-sharing system was designed on the basis of a well-developed philosophy of the facilities a time-sharing utility should provide its users and the form in which the two should communicate. The philosophy includes concern for symmetry and completeness of the facilities provided, simplicity of input formats, confirmation of potentially disastrous effects, full use of the capabilities of the terminal, compatibility between batch and interactive use, and the Law of Least Astonishment. These philosophical principles are implemented in COMMANDER II in part by a system call which parses and dispatches a command for processing based on a table which describes the legal command imperatives and the associated parameters, default values, prompting structure, and so on.