gopkg.in/vbauerster/mpb.v1

Multi Progress Bar

mpb is a Go lib for rendering progress bars in terminal applications.

It is inspired by uiprogress library, but unlike the last one, implementation is mutex free, following Go's idiom:

Don't communicate by sharing memory, share memory by communicating.

Features

• Multiple Bars: mpb can render multiple progress bars that can be tracked concurrently
• Cancellable: cancel rendering goroutine at any time
• Dynamic Addition: Add additional progress bar at any time
• Dynamic Removal: Remove rendering progress bar at any time
• Dynamic Sorting: Sort bars as you wish
• Dynamic Resize: Resize bars on terminal width change
• Custom Decorator Functions: Add custom functions around the bar along with helper functions
• Predefined Decoratros: Elapsed time, Ewmaest based ETA, Percentage, Bytes counter

Usage

Following is the simplest use case:

	// Star mpb's rendering goroutine.
	// If you don't plan to cancel, feed with nil
	// otherwise provide context.Context, see cancel example
	p := mpb.New(nil)
	// Set custom width for every bar, which mpb will contain
	// The default one in 70
	p.SetWidth(80)
	// Set custom format for every bar, the default one is "[=>-]"
	p.Format("╢▌▌░╟")
	// Set custom refresh rate, the default one is 100 ms
	p.RefreshRate(120 * time.Millisecond)

	// Add a bar. You're not limited to just one bar, add many if you need.
	bar := p.AddBar(100).PrependName("Single Bar:", 0).AppendPercentage()

	for i := 0; i < 100; i++ {
		bar.Incr(1) // increment progress bar
		time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond)
	}

	// Don't forget to stop mpb's rendering goroutine
	p.Stop()

	// You cannot add bars after p.Stop() has been called
	// p.AddBar(100) // will panic

Running this, will produce:

However mpb was designed with concurrency in mind. Each new bar renders in its own goroutine, therefore adding multiple bars is easy and safe:

	var wg sync.WaitGroup
	p := mpb.New(nil)
	for i := 0; i < 3; i++ {
		wg.Add(1) // add wg delta
		name := fmt.Sprintf("Bar#%d:", i)
		bar := p.AddBar(100).PrependName(name, len(name)).AppendPercentage()
		go func() {
			defer wg.Done()
			// you can p.AddBar() here, but ordering will be non deterministic
			// if you still need p.AddBar() here and maintain ordering, use
			// (*mpb.Progress).BeforeRenderFunc(f mpb.BeforeRender)
			for i := 0; i < 100; i++ {
				bar.Incr(1)
				time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond)
			}
		}()
	}
	wg.Wait() // Wait for goroutines to finish
	p.Stop()  // Stop mpb's rendering goroutine
	// p.AddBar(1) // panic: you cannot reuse p, create new one!
	fmt.Println("finish")

The source code: example/simple/main.go

Cancel

The source code: example/cancel/main.go

Removing bar

The source code: example/remove/main.go

Sorting bars by progress

The source code: example/sort/main.go

Resizing bars on terminal width change

The source code: example/prependETA/main.go

Multiple io

The source code: example/io/multiple/main.go

Custom Decorators

Here is example from getparty src code.

Installation

$ go get -u github.com/vbauerster/mpb

License

MIT

The typeface used in screen shots: Iosevka