Why the negative 1?

[Zane Hitchcox]

For gosh sake's I've been trying to debug my own code for a while now, and I look to your code for inspiration, and the thing that fixed it was changing

syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)

syscall.Kill(-1*cmd.Process.Pid, syscall.SIGKILL)

as you did in your code. I just thought it looked odd and there must be a reason for it, so I tried it and it fixed my code!!!

So, I just have to ask why on earth. I guess it's casting it to an int? But why does that matter?

[Caleb Spare]

Those are equivalent. I like your way better. I think that maybe changing that wasn't having the effect you thought it was?

[Zane Hitchcox]

Haha, yes, I found out the actual reason was I was intercepting the signal to kill, but that was just on my test script, not the actual script... have to figure out if it was the same problem in my actual code tomorrow

[Zane Hitchcox]

Yeah, it turns out I had this code

	c := make(chan os.Signal, 2)
	signal.Notify(c, os.Interrupt, os.Kill)
	go func() {
		<-c
		syscall.Kill(-serverCmd.Process.Pid, syscall.SIGKILL)
		os.Exit(1)
	}()

that was keeping the process alive.

goroutines are hard :(

Thanks for your help though!

[Zane Hitchcox]

Basically, the problem is I'm running this code

	c := make(chan os.Signal, 2)
	signal.Notify(c, os.Interrupt, os.Kill)
	go func() {
		defer close(c)
		<-c
		syscall.Kill(-apiCmd.Process.Pid, syscall.SIGKILL)
		syscall.Kill(-uiCmd.Process.Pid, syscall.SIGKILL)
		os.Exit(1)
	}()

	go func() {
		apiCmd = exec.Command("go", "run", "./scripts/watch-server.go")
		apiCmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
		apiCmd.Stdout = os.Stdout
		apiCmd.Stderr = os.Stderr
		apiCmd.Run()
	}()

	uiCmd = exec.Command("yarn", "dev:ui")
	uiCmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
	uiCmd.Stdout = os.Stdout
	uiCmd.Stderr = os.Stderr
	uiCmd.Run()

And if I don't run the apiCmd in a goroutine, it never runs the uiCmd, but if I take it out, when I end the process, the apiCmd keeps running even after I end the process.

[Zane Hitchcox]

Ok, finally fixed it...this is my code if you're interested

package main

import (
	"log"
	"os"
	"os/exec"
	"os/signal"
	"syscall"
)

var apiCmd, uiCmd *exec.Cmd

func main() {
	c := make(chan os.Signal, 2)
	signal.Notify(c, os.Interrupt, os.Kill)
	go func() {
	}()

	go func() {
		apiCmd = exec.Command("go", "run", "./scripts/watch-server.go")
		apiCmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
		apiCmd.Stdout = os.Stdout
		apiCmd.Stderr = os.Stderr
		apiCmd.Run()
	}()

	go func() {
		uiCmd = exec.Command("yarn", "dev:ui")
		uiCmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
		uiCmd.Stdout = os.Stdout
		uiCmd.Stderr = os.Stderr
		uiCmd.Run()
	}()
	defer close(c)
	<-c
	log.Println("closing")
	syscall.Kill(-apiCmd.Process.Pid, syscall.SIGKILL)
	syscall.Kill(-uiCmd.Process.Pid, syscall.SIGKILL)
	os.Exit(1)
}