How to Create a Waiting/Busy Indicator for Executed Processes in Go?

Creating Waiting/Busy Indicator for Executed Process

When executing child processes in Go, such as installing npm packages using exec.Command, it can take a significant amount of time before output is visible. To enhance the user experience, consider displaying a busy indicator to indicate that the process is in progress.

Solution:

One effective solution involves using a separate goroutine to periodically print characters, such as dots, to the console while the process is running. When the process completes, the indicator goroutine can be terminated.

<code class="go">func indicator(shutdownCh <-chan struct{}) {
    ticker := time.NewTicker(time.Second)
    defer ticker.Stop()
    for {
        select {
        case <-ticker.C:
            fmt.Print(".")
        case <-shutdownCh:
            return
        }
    }
}

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

    // Start indicator:
    shutdownCh := make(chan struct{})
    go indicator(shutdownCh)

    err := cmd.Run()

    close(shutdownCh) // Signal indicator() to terminate

    fmt.Println()
    log.Printf("Command finished with error: %v", err)
}</code>

For a more visually appealing indicator, you can modify the indicator function to print a newline after a specific number of dots, such as 5:

<code class="go">func indicator(shutdownCh <-chan struct{}) {
    ticker := time.NewTicker(time.Second)
    defer ticker.Stop()
    for i := 0; ; {
        select {
        case <-ticker.C:
            fmt.Print(".")
            if i++; i%5 == 0 {
                fmt.Println()
            }
        case <-shutdownCh:
            return
        }
    }
}</code>

By implementing this solution, you can provide a visual cue to users indicating that a process is executing, enhancing the user experience and making the application more responsive.

The above is the detailed content of How to Create a Waiting/Busy Indicator for Executed Processes in Go?. For more information, please follow other related articles on the PHP Chinese website!