CIO >sb: Copy bytes from serial channel A onto serial channel B until is pressed or an end-of-file (normally control-D) is received. Alt C CIO >cent: Print the file ‘myfile’ out on the parallel printer. Shell file commands Echo command line arguments ECHO [-n] [arg1] [arg2] The ECHO command simply prints its arguments out. If the first argument is ‘-n’ then a new-line is not printed out after the arguments. This command is mainly used within shell (executable text) files. For example, suppose one creates a shell program file (called ‘sum’) containing the following lines: ECHO -n "Adding " " and " " produces " EXPR + When this shell program is executed with two numeric arguments (e.g.
‘sum 1 2’) the appropriate output results. You can echo characters that have an audible effect, such as the or beeps. Note that you can alter the volume and sound of a beep using the oscontrol() system call. Ctrl G Ctrl B Pausing PAUSE n1 ThePAUSEcommand causes 1616/OS toceaseprocessingcommandsfor aduration of ‘n1’ twenty millisecond system timer ticks. In otherwords the pause length is (n1 / 50) seconds long. An interrupts a pause. Alt C PAUSE is designed for inclusion in shell program files to allow users time to read the contents of the screen before new commands from within the shell file are executed. Remember that the default form of numeric input is hexadecimal! Put a full stop .
’) in front of decimal pause lengths. For example consider the following shell program (called ‘memex’): ECHO "To observe memory alteration" ECHO ECHO "Memory before executing " MDL PAUSE .100 ;2 seconds Page 82 User Tutorial Manual 1616/OS Commands