On Fri, Jan 01, 2021 at 10:02:26PM +0100, Ángel wrote: > Yes. In fact, you can already do that using an interface exactly > identical to file operations: > > # Store a string in shared memory with key 'foo' > echo "Hello world" > foo > > # Read value of key foo > var="$(<foo)" > > > You only need to use that on a tmpfs filesystem, and it will be stored > in memory. Or, if you wanted to persist your shared memory between > reboots, or between machines, you could place them instead on a local > or networked filesystem.
It should be noted that $(<foo) still forks a process. If you want the script to be faster, you'll need some other way to read the data from the file -- perhaps using the read -r -d '' command, or the mapfile command. Other forms of IPC that are viable in scripts include using a FIFO that's held open by both parent and child, or launching the child as a coprocess.
