A Go library to render progress bars in terminal applications. It provides a set of powerful features that are customizable using a simple interface.

Progress bars improve readability for terminal applications with long outputs by providing a concise feedback loop.

• Multiple Bars: uiprogress can render multiple progress bars that can be tracked concurrently
• Dynamic Addition: Add additional progress bars any time, even after the progress tracking has started
• Prepend and Append Functions: Append or prepend completion percent and time elapsed to the progress bars
• Custom Decorator Functions: Add custom functions around the bar along with helper functions

To start listening for progress bars, call uiprogress.Start() and add a progress bar using uiprogress.AddBar(total). Update the progress using bar.Set(n). Full source code for the below example is available at example/simple/simple.go

uiprogress.Start() // start rendering
bar := uiprogress.AddBar(100) // Add a new bar
// optionally, append and prepend completion and elapsed time
bar.AppendCompleted()
bar.PrependElapsed()

for i := 1; i <= bar.Total; i++ {
  bar.Set(i)
  time.Sleep(time.Millisecond * 10)
}

This will render the below in the terminal

You can also add a custom decorator function in addition to default bar.AppendCompleted() and bar.PrependElapsed() decorators. The below example tracks the current step for an application deploy progress. Source code for the below example is available at example/full/full.go

var steps = []string{"downloading source", "installing deps", "compiling", "packaging", "seeding database", "deploying", "staring servers"}
bar := uiprogress.AddBar(len(steps))
// prepend the current step to the bar
bar.PrependFunc(func(b *uiprogress.Bar) string {
  return "app: " + steps[b.Current()-1]
})

for i := 0; i < bar.Total; i++ {
  bar.Set(i + 1)
  time.Sleep(time.Millisecond * 100)
}

You can add multiple bars using uiprogress.AddBar(n). The below example demonstrates updating multiple bars concurrently and adding a new bar later in the pipeline. Source for this example is available at example/multi/multi.go

waitTime := time.Millisecond * 100
uiprogress.Start()
var wg sync.WaitGroup

// update the progress bars concurrently using a go routine
bar1 := uiprogress.AddBar(20).AppendCompleted().PrependElapsed()
wg.Add(1)
go func() {
  defer wg.Done()
  for i := 1; i <= bar1.Total; i++ {
    bar1.Set(i)
    time.Sleep(waitTime)
  }
}()

bar2 := uiprogress.AddBar(100).AppendCompleted().PrependElapsed()
wg.Add(1)
go func() {
  defer wg.Done()
  for i := 1; i <= bar2.Total; i++ {
    bar2.Set(i)
    time.Sleep(waitTime)
  }
}()

time.Sleep(time.Second) // some logic
bar3 := uiprogress.AddBar(20).PrependElapsed().AppendCompleted()
wg.Add(1)
go func() {
  defer wg.Done()
  for i := 1; i <= bar3.Total; i++ {
    bar3.Set(i)
    time.Sleep(waitTime)
  }
}()
// wait for a collection of goroutines to finish
wg.Wait()

This will produce

$ go get -v github.com/gosuri/uiprogress

• Resize bars and decorators by auto detecting window's dimensions
• Handle more progress bars than vertical screen allows

uiprogress is released under the MIT License. See LICENSE.