The BACK function returns the names of all currently executing programs, listed one name on each line in a multiline text value. When more than one program is executing, this means that 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.
The following example uses three programs.
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
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