BACK

The BACK function returns the names of all currently executing programs, listed one name on each line in a multiline text value. When multiple programs are executing, one program has called another in a series of nested executions.

The first name in the return value is that of the program containing the call to BACK. The last name is that of the initial program, which made the first call to another program.

BACK can only be used in a program.

Return Value

TEXT

Syntax

BACK

Examples

Example 7-27 Debugging a Program Using the BACK Function

The following example uses three programs. program1 calls program2, and program2 calls program3.

DEFINE program1 PROGRAM
PROGRAM
SHOW 'This is program number 1'
CALL program2
END
DEFINE program2 PROGRAM
PROGRAM
SHOW 'This is program number 2'
CALL program3
END
DEFINE program3 PROGRAM
PROGRAM
SHOW 'This is program number 3'
SHOW 'These programs are currently executing:'
SHOW BACK
END

Executing program1 produces the following output.

This is program number 1
This is program number 2
This is program number 3
These programs are currently executing:
PROGRAM3
PROGRAM2
PROGRAM1