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ESCAPE |
Interrupt Program Execution |
ESCAPE [err_val] [ON | OFF]
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err_val |
Optional numeric value to be placed in the ERR variable. (PxPlus interprets this as an error code and the system logic kicks in.) |
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ESCAPE ON |
Restores the standard functioning of the ESCAPE directive with no error value, which is to halt processing and enter Command mode. |
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ESCAPE OFF |
Causes the system to ignore any ESCAPE directives that do not have error values, which would normally cause processing to halt and enter Command mode. |
When you use the ESCAPE directive in Execution mode, PxPlus suspends execution of the current program, lists the current statement (the line number with the ESCAPE directive), and returns you to Command mode. Use the RUN directive to have the program resume where it left off.
You can simplify the debugging process by placing ESCAPE statements strategically in your program. When execution is suspended, you are returned to Command mode, where you can evaluate execution and the values of variables, etc. (up to the line where you placed the ESCAPE in your application).
If you enter ESCAPE in Command mode, PxPlus lists the next statement to be processed, if any. If you specify an error value, the ESCAPE directive will generate an error with that specific error value. Use this to provide an error exit in a multi-line function.
The *ESCAPE label emulates an ESCAPE directive for use as a statement reference.
DEF FN Define Function
Labels/Logical Statement References
0100 print "BEGIN"; escape; print "DONE"
When 'run', this would yield:
BEGIN
0100 PRINT "BEGIN"; ESCAPE ; PRINT "DONE"
1> (Command mode prompt)
Entry of a 'run' command would yield:
DONE