A very simple thread-safe progress bar which should work on every OS without problems. I needed a progressbar for croc and everything I tried had problems, so I made another one. In order to be OS agnostic I do not plan to support multi-line outputs.

go get -u github.com/schollz/progressbar/v3

bar := progressbar.Default(100)
for i := 0; i < 100; i++ {
    bar.Add(1)
    time.Sleep(40 * time.Millisecond)
}

which looks like:

The progressbar implements an io.Writer so it can automatically detect the number of bytes written to a stream, so you can use it as a progressbar for an io.Reader.

req, _ := http.NewRequest("GET", "https://dl.google.com/go/go1.14.2.src.tar.gz", nil)
resp, _ := http.DefaultClient.Do(req)
defer resp.Body.Close()

f, _ := os.OpenFile("go1.14.2.src.tar.gz", os.O_CREATE|os.O_WRONLY, 0644)
defer f.Close()

bar := progressbar.DefaultBytes(
    resp.ContentLength,
    "downloading",
)
io.Copy(io.MultiWriter(f, bar), resp.Body)

which looks like:

A progressbar with unknown length is a spinner. Any bar with -1 length will automatically convert it to a spinner with a customizable spinner type. For example, the above code can be run and set the resp.ContentLength to -1.

which looks like:

There is a lot of customization that you can do - change the writer, the color, the width, description, theme, etc. See all the options.

bar := progressbar.NewOptions(1000,
    progressbar.OptionSetWriter(ansi.NewAnsiStdout()), //you should install "github.com/k0kubun/go-ansi"
    progressbar.OptionEnableColorCodes(true),
    progressbar.OptionShowBytes(true),
    progressbar.OptionSetWidth(15),
    progressbar.OptionSetDescription("[cyan][1/3][reset] Writing moshable file..."),
    progressbar.OptionSetTheme(progressbar.Theme{
        Saucer:        "[green]=[reset]",
        SaucerHead:    "[green]>[reset]",
        SaucerPadding: " ",
        BarStart:      "[",
        BarEnd:        "]",
    }))
for i := 0; i < 1000; i++ {
    bar.Add(1)
    time.Sleep(5 * time.Millisecond)
}

which looks like:

Pull requests are welcome. Feel free to...

• Revise documentation
• Add new features
• Fix bugs
• Suggest improvements

Thanks @Dynom for massive improvements in version 2.0!

Thanks @CrushedPixel for adding descriptions and color code support!

Thanks @MrMe42 for adding some minor features!

Thanks @tehstun for some great PRs!

Thanks @Benzammour and @haseth for helping create v3!

Thanks @briandowns for compiling the list of spinners.

MIT