Creating waiting/busy indicator for executed process

Question

i\'ve program which execute child process like

cmd := exec.Command(\"npm\", \"install\")
log.Printf(\"Running command and waiting for it to finish...\")
err         


        

Answer 1

Another way is to turn icza's answer around. Since the npm command is a long-running execution, it would probably be better to use a goroutine for it instead of the ticker (or both as a goroutine), but it's a matter of preference.

Like this:

func npmInstall(done chan struct{}) {
    cmd := exec.Command("npm", "install")
    log.Printf("Running command and waiting for it to finish...")

    err := cmd.Run()
    if err != nil {
        log.Printf("\nCommand finished with error: %v", err)
    }
    close(done)
}

func main() {
    done := make(chan struct{})
    go npmInstall(done)

    ticker := time.NewTicker(3 * time.Second)
    defer ticker.Stop()
    for {
        select {
        case <-ticker.C:
            fmt.Print(".")
        case <-done:
            fmt.Println()
            return
        }
    }
}