Why the negative 1?

[zwhitchcox]

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?

[cespare]

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

[zwhitchcox]

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

[zwhitchcox]

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!

[zwhitchcox]

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.

[zwhitchcox]

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)
}