ph4-acmd2 0.0.6

Cmd2 extension for async programs

Async extension to a famous Cmd2 library.

Cmd2 permanently occupies the main thread which is a problem if you plan to receive callbacks on the main thread (e.g., by Bluetooth stack Bleak)

Pip installation

BoolTest is available via pip:

pip3 install ph4-acmd2

Local installation

From the local dir:

pip3 install --upgrade --find-links=. .

Usage

import asyncio
import ph4acmd2

class CmdLineApp(ph4acmd2.Cmd):
    async def main(self):
        await self.acmdloop()
        print("Cmdloop finished now")

if __name__ == '__main__':
    app = CmdLineApp()
    loop = asyncio.get_event_loop()
    loop.set_debug(True)
    loop.run_until_complete(app.main())

Limitations

We use asyncio.lool.add_reader to read from the stdin and process the commands thus it is not currently possible to ue readline features such as auto-complete or ctrl-r, UP-arrow for previous commands, etc…

Readline occupies main thread in a blocking way, so it is not compatible with runloop model running on the main thread and executing coroutines.

In order to use readline it needs to add async support. A potential workaround could be to access terminal in async way e.g., submit short coroutine monitoring the terminal state to simulate readline library. However, it is not tested.