How to kill subprocess on terminating main process in Go language

Question

I want to kill subprocesses when main process is terminating.

I am running the subprocess with exec.Command()

However the main process can be terminated by an unexpected error so I want to be sure the subprocess also be terminated too.

How to archive it in Go language?

Answer 1

You might want to use CommandContext instead, and cancel the context when your main process is being terminated. Below are two examples: the first one is for a simple demonstration of terminating a process after a short timeout, the second is for terminating a sub-process when your process catches external termination signal from the OS:

package main

import (
    "context"
    "os/exec"
    "time"
    "os/signal"
)

func main() {
    // terminate the command based on time.Duration
    ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
    defer cancel()

    if err := exec.CommandContext(ctx, "sleep", "5").Run(); err != nil {
        // This will fail after 100 milliseconds. The 5 second sleep
        // will be interrupted.
    }

    // or use os signals to cancel the context
    ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
    defer stop()
}