At times you may want to gain access to or control another process on the system—either a user process or a phantom process (a process that is not linked or attached to any port). This may be necessary, for example, when a user’s terminal can not access the user process to which it is connected (either the terminal or the process may have hung.)
The POKE command lets you insert TCL commands into the input buffer of another process and execute them there. The TANDEM command lets you access and control another process from your own terminal. Using TANDEM you can access any user or phantom process. If you use TANDEM to access a process that is connected to another user’s terminal, that process, along with all its input and output, is run simultaneously on both terminals.
Executing Commands on Other Processes with POKE
When you enter the POKE command at TCL, you enter POKE mode and remain there until you enter an @ at the prompt, which is a pound sign (#). You are prompted to enter the number of the process on which you want to execute a command followed by the command to be executed. Only commands contained in the target process’s Master Dictionary can be executed using POKE. The command and its output will be displayed on the terminal connected to the target process; they will not be displayed on your own process.
Controlling Other Processes with TANDEM
The TANDEM command gives you even more flexibility in monitoring and controlling processes. TANDEM actually displays all input and output of another process on your screen, and allows you to send input to the other process either as nonexecutable messages or as executable commands. The TANDEM command requires SYS3 privileges.
When you enter the TANDEM command at TCL, you enter the View Mode of TANDEM. View Mode only lets you observe the target process’s input and output. To send messages to be displayed on the target process’s screen, press ESC+M, to enter Message Mode. No input entered while you are in Message Mode will be used for processing. To execute commands on the target process, press ESC+F, to enter Feed Mode. You can also force the target process into the Debugger by pressing ESC+D.
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NOTE |
If the Debugger has been disabled on the target process, pressing ESC+D has no effect. |
To exit TANDEM, press ESC+X.
See Also