6.7 Exiting From ACUCOBOL-GT Programs

If an application written in ACUCOBOL-GT is aborted, the following exit techniques produce different results:

Catastrophic exit: A power failure, turning off the computer, or issuing a "kill -9" from the console are all examples of catastrophic exits. The runtime cannot trap exits of this kind. Any files open at the time of a catastrophic exit may be corrupted.
Graceful abort: A "kill" ( not a "kill -9") from the console and a Control-C from the keyboard are forms of program abort that ACUCOBOL-GT tries to detect. If the abort signal is intercepted by the runtime system, the runtime will close any open files and set the user count back.
Safe mode exit: The runtime option "-s" instructs the runtime to trap graceful abort signals such as Control-C and prevent the abort from occurring. Only normally coded exit paths are allowed in safe mode.

Note that even in safe mode, the runtime cannot trap a catastrophic exit. So even if you run with "-s", turning off the computer or issuing a "kill -9" will risk corrupting the file.