> a low level pretend filesystem driver Plan 9 IS NOT Linux or Unix. It is a pure VFS and only speaks 9p. A plan 9 file server serves a real file system. Think

> a low level pretend filesystem driver Plan 9 IS NOT Linux or Unix. It is a pure VFS and only speaks 9p. A plan 9 file server serves a real file system. Think of the file server as an abstraction that closely resembles a micro service. It handles the multiplexing of multiple clients who might want/need to open the same file. If you have a sign that takes formatted text via RS232 then you don't need the file server or the logic as the sign already handles this. You just need to write text to /dev/eia0 or whatever. Setting the com port settings is done via the com ports control file /dev/eia0ctl. This means you can use a shell script to set the com port settings by echoing the baud and all that into the ctl file. However, what if you bought an LED panel that was just a bunch of LED's? It doesn't understand text or formatting so now you need to hook it to a CPU and write code. In this case, a file server running on a pi would be a great interface to handle that. The server would contain the logic to accept a formatted string of text and turn that into glowing LED's. Then any program can open that file to operate the display like a script, python program, or web server.