How to run a process in background and get his pid ?

[antkern]

Hello

Is it possible to run a process in background and get is pid ?

The following code fails :

tshark -i lo -f udp & 
echo $! > PATH.PID

Thank you

[antkern]

Now i'm using a python code to bypass the problem

start_capture:
    #!/usr/bin/env python3
    import subprocess
    process = subprocess.Popen(["tshark", "-i", "lo", "-f", "udp"])
    with open("{{ CAPTURE_PATH }}.pid", "w") as out:
        out.write(str(process.pid))

[Taywee]

You can also use a shell shebang do bypass the problem.

In a normal Just recipe, each line is run in its own shell, so you can't refer to variables set in previous lines. Shebang recipes run the entire body through the selected interpreter. This should also work for you:

start_capture:
    #!/bin/sh
    tshark -i lo -f udp & 
    echo $! > PATH.PID