uilive

README

uilive

uilive is a go library for updating terminal output in realtime. It provides a buffered io.Writer that is flushed at a timed interval. uilive powers uiprogress.

Usage Example

Calling uilive.New() will create a new writer. To start rendering, simply call writer.Start() and update the ui by writing to the writer. Full source for the below example is in example/main.go.

writer := uilive.New()
// start listening for updates and render
writer.Start()

for i := 0; i <= 100; i++ {
  fmt.Fprintf(writer, "Downloading.. (%d/%d) GB\n", i, 100)
  time.Sleep(time.Millisecond * 5)
}

fmt.Fprintln(writer, "Finished: Downloaded 100GB")
writer.Stop() // flush and stop rendering

The above will render

Installation

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

Documentation

Overview

Package uilive provides a writer that live updates the terminal. It provides a buffered io.Writer that is flushed at a timed interval.

Example

package main

import (
	"fmt"
	"time"

	"github.com/gosuri/uilive"
)

func main() {
	writer := uilive.New()

	// start listening to updates and render
	writer.Start()

	for i := 0; i <= 100; i++ {
		fmt.Fprintf(writer, "Downloading.. (%d/%d) GB\n", i, 100)
		time.Sleep(time.Millisecond * 5)
	}

	fmt.Fprintln(writer, "Finished: Downloaded 100GB")
	writer.Stop() // flush and stop rendering
}

Index

• Constants
• Variables
• type FdWriter
• type Writer
  • func New() *Writer
  • func (w *Writer) Bypass() io.Writer
  • func (w *Writer) Flush() error
  • func (w *Writer) Listen()
  • func (w *Writer) Newline() io.Writer
  • func (w *Writer) Start()
  • func (w *Writer) Stop()
  • func (w *Writer) Write(buf []byte) (n int, err error)

Examples

• Package

Constants

const ESC = 27

ESC is the ASCII code for escape character

Variables

var ErrClosedPipe = errors.New("uilive: read/write on closed pipe")

ErrClosedPipe is the error returned when trying to writer is not listening

var Out = io.Writer(os.Stdout)

Out is the default output writer for the Writer

var RefreshInterval = time.Millisecond

RefreshInterval is the default refresh interval to update the ui

Types

type FdWriter

type FdWriter interface {
	io.Writer
	Fd() uintptr
}

FdWriter is a writer with a file descriptor.

type Writer

type Writer struct {
	// Out is the writer to write to
	Out io.Writer

	// RefreshInterval is the time the UI sould refresh
	RefreshInterval time.Duration
	// contains filtered or unexported fields
}

Writer is a buffered the writer that updates the terminal. The contents of writer will be flushed on a timed interval or when Flush is called.

func New

func New() *Writer

New returns a new Writer with defaults

func (*Writer) Bypass

func (w *Writer) Bypass() io.Writer

Bypass creates an io.Writer which allows non-buffered output to be written to the underlying output

func (*Writer) Flush

func (w *Writer) Flush() error

Flush writes to the out and resets the buffer. It should be called after the last call to Write to ensure that any data buffered in the Writer is written to output. Any incomplete escape sequence at the end is considered complete for formatting purposes. An error is returned if the contents of the buffer cannot be written to the underlying output stream

func (*Writer) Listen

func (w *Writer) Listen()

Listen listens for updates to the writer's buffer and flushes to the out provided. It blocks the runtime.

func (*Writer) Newline

func (w *Writer) Newline() io.Writer

Newline creates an io.Writer which allows buffered output to be written to the underlying output. This enable writing to multiple lines at once.

func (*Writer) Start

func (w *Writer) Start()

Start starts the listener in a non-blocking manner

func (*Writer) Stop

func (w *Writer) Stop()

Stop stops the listener that updates the terminal

func (*Writer) Write

func (w *Writer) Write(buf []byte) (n int, err error)

Write save the contents of buf to the writer b. The only errors returned are ones encountered while writing to the underlying buffer.