3 Command Handling The 1616 is made to do things by typing commands at the keyboard. If the command is not correctly typed, then an error message is produced. A command is simply the name of a program, or the name of an inbuilt command or system call. In many cases, the command or program requires parameters , or arguments . A parameter or argument modifies the effects of a command, by telling it which of several possible things you want done. Some commands accept more than one type of parameter. Some accept multiple instances of a single type of parameter. This chapter explains the general form of commands, their syntax, and gives examplesofsomesimplecommandsfor youtotry.
TheApplixcanaccept numbers indecimal(theway humanswrite numbers),hexadecimal(the default,ascomputer numbersare usuallyexpressed thisway)orbinary(theway computersuse numbers internally). This chapter explains how to use each form. Punctuation and special characters are important when issuing computer com- mands; these are listed. The general way commands are executed (obeyed) by the computer is covered. A brief explanation is given of the very powerful redirection facilities of the Applix 1616. Wildcard expansion is explained, showing how you can avoid typing full details of filenames, and instead let the computer work them out.
General command format The general format for the entry of commands is: commandname arguments inputsource > outputdestination } errordestination ‘Commandname’ is the name of the command (see the full list later in this manual) whichisbeingused. We shownamesofcommandsand namesoffilesina courier typeface, to make it easier to identify them in the manual. ‘Arguments’ refers to any additional instructions or data which the specific command needs. The special redirection operators , > , and } are explained later. They make it possible to use computer files, or devices other than the keyboard, for entering material.
They also allow the results of the command to be displayed somewhere other than the normal display screen, such as on the printer, or on another computer via a serial port. Command Handling User Tutorial Manual Page 21