While a system process is running, it remains in control of your terminal. Typically, you want the system process to complete its work and return control to the TCL level. If you press BREAK while a process is running, you will suspend the process and drop into a debugger.

The debugger is used to examine the state of a program as it is executing. The system debugger is identified by an exclamation mark (!) prompt.

Use the following debugger commands as needed:
Command Description
G Enter this command when you unintentionally break out of a program and need to resume the execution of the process.
END Enter this command to terminate the suspended process and return to TCL.
OFF Enter this command to log off the system.

For example, to exit to the TCL prompt from the system debugger, type END and press Enter.

Be extremely cautious in exiting a process because it might have been updating items in a file. Consult with your system administrator if you enter the debugger unexpectedly.
The BREAK key can be enabled or disabled using the break-key-on macro and break-key-off macro, respectively. By default, the BREAK key is enabled. It can be disabled by placing B in Attribute 9 of the Account Definition item.
Note: End-user applications usually disable the BREAK key. This action denies users access to the debugger.


Determine what BREAK sequence your client supports. Some Telnet clients do not support hard breaks. The Telnet protocol defines both the BREAK and IP (Interrupt Process) codes. Both of these codes are used by Telnet to generate a BREAK-KEY signal to the server line. If your Telnet client supports neither of these, choose a soft break using a control character, such as Ctrl+C, and then use the set-break command from TCL to set that character as a soft break key for your line.

To stop executing the statements stored in the file item, press BREAK. Even though all of the statements in the file item have not been executed, they will all be stored in the stack.

A helpful practice is to create a standard file called TC (for Terminal Commands) to which you can routinely copy (.C) and execute (.R) stack statements.