GLOBAL variable-name = expression

Marks a variable assignment as global-for-child-processes. The variable’s current value is copied (not referenced) into any new programs this program creates (for example via CHAIN). This mechanism is also how rocketsh passes command-line style parameters into a program.

Note: GLOBAL must appear with an assignment.; GLOBAL without an assignment is invalid.

Behaviour

The assignment executes normally in the current program, and the variable is flagged so that its value is copied into subsequently created child programs.
The copy happens at child creation time. Changes made later in either parent or child do not affect the other.
To keep a variable marked as global, every subsequent assignment to that variable must also be written with GLOBAL.
- If you assign to the variable without GLOBAL, it will no longer be treated as global for future child launches.

Examples

Pass a string and number to a child

Parent program:

GLOBAL USERNAME$ = "guest"
GLOBAL TIMEOUT   = 30
 
CHAIN "childprog"
PRINT "Back in parent."

Child program (childprog):

PRINT "User: "; USERNAME$

PRINT "Timeout: "; TIMEOUT

Losing the global mark by plain assignment

GLOBAL MODE$ = "SAFE"
MODE$ = "FAST"
CHAIN "worker"

To keep MODE$ global for future children:

GLOBAL MODE$ = "FAST"

Notes

GLOBAL controls inter-program passing only. It does not create a program-wide scope within a single program.
The variable is copied by value into the child at launch.
Use GLOBAL only on lines that assign to the variable.

See also:
CHAIN