Yes, superglobal is great.
Example, from the manual:
" Shared Memory
Shared memory allows one or more processes to communicate via memory that
appears in all of their virtual address spaces. The pages of the virtual
memory is referenced by page table entries in each of the sharing
processes' page tables. It does not have to be at the same address in all
of the processes' virtual memory. As with all System V IPC objects, access
to shared memory areas is controlled via keys and access rights checking.
Once the memory is being shared, there are no checks on how the processes
are using it. They must rely on other mechanisms, for example System V
semaphores, to synchronize access to the memory."
We could allow only strings or more complex objects, but using bash-language
only, an internal mechanism, and also we need to define a semaphore.
Is it doable?