prompt_appearing_immediately.go

// The following code works fine:
//
//   $ ./signals-test 
//   ^CSignal received, handler unregistered...
//   ^C
//   $

package main

import (
    "fmt"
    "os"
    "os/signal"
    "time"
)

func main() {
    ch := make(chan os.Signal, 1)
    signal.Notify(ch, os.Interrupt)
    go catchSignals(ch)

    time.Sleep(60 * time.Second)
}

func catchSignals(ch chan os.Signal) {
    <-ch
    fmt.Println("Signal received, handler unregistered...")
    signal.Stop(ch)
}

// The following code works in a strange way, the prompt appears immediately:
//
//   $ ./signals-test
//   ^CSignal received, handler unregistered...
//   $
//
// When I run ps now, there is no signals-test process.
// Looks like the difference is the spawning of a new process, dunno why...

package main

import (
    "fmt"
    "os"
    "os/exec"
    "os/signal"
)

func main() {
    ch := make(chan os.Signal, 1)
    signal.Notify(ch, os.Interrupt)
    go catchSignals(ch)

    cmd := exec.Command("sleep", "60")
    cmd.Run()
}

func catchSignals(ch chan os.Signal) {
    <-ch
    fmt.Println("Signal received, handler unregistered...")
    signal.Stop(ch)
}