Allow real/external ports to be used in the group of ports

[rsend]

Hi,
Not sure if your project covers this use case, but I feel like it could - I just can't quite figure out how. In my application I need to forward (and modify) traffic between an application that expects to open a physical port (or descriptor), and the actually existing port. The default topology looks like this:

• App opens existing /dev/ttyX.

What I did:

• Create port pair that echoes between them
• App opens one virtual serial port <-> Python opens the other virtual port, then processes traffic -> Python sends to existing /dev/ttyX.

What I'm wondering: Can this library help remove one of the two virtual ports and just do this:

• App opens -> Python virtual serial port, process traffic -> Python sends to existing /dev/ttyX/.

If I use this library to create one /dev/pts0, how do I interact with it from within Python? That part is unclear to me.

[ezramorris]

Hi, appreciate this has been over a year since you posted it, so apologies.

So far, the focus has been on creating combinations of virtual ports, rather than interfacing with real ports. Next I'm looking at Windows support. However, I think this is a great idea and something which I will consider.

For now, you may be interested to have a look at the implementation; in particular (as of 2.0.0) the open() and process() methods. Basically we create a pty port pair, which gives a 'master', which the library uses for internal processing, and a 'slave' which is the /dev/pty/X externally accessible. For a simple use case, you could create a script based on this which sends data between the master and the real serial port, instead of between two masters.

It is possible to use PyVirtualSerialPorts to do this in a single script with version 2.0.0. It has been refactored to be much more useful as a library. A basic example has been created to demonstrate this in example.py. For your case, you could implement this in one script rather than having to wait for the port pair to be produced to know which PTYs are being used. However, this will still end up with an overly-complicated solution for what you need.