Basically works

README.md

@@ -0,0 +1,13 @@
+<p align="center">
+<img
+    src="logo.png"
+    width="100%" border="0" alt="progressbar">
+<br>
+<a href="https://travis-ci.org/schollz/progressbar"><img src="https://travis-ci.org/schollz/progressbar.svg?branch=master" alt="Build Status"></a>
+<a href="https://goreportcard.com/report/github.com/schollz/progressbar"><img src="https://goreportcard.com/badge/github.com/schollz/progressbar" alt="Go Report Card"></a>
+<a href="https://godoc.org/github.com/schollz/progressbar"><img src="https://godoc.org/github.com/schollz/progressbar?status.svg" alt="GoDoc"></a>
+</p>
+
+<p align="center">A very simple progress bar.</p>
+
+See the godocs for more info.

examples/main.go

@@ -1,15 +1,16 @@
-package main
-
-import (
-	"time"
-
-	"github.com/schollz/progressbar"
-)
-
-func main() {
-	bar := progressbar.New(100)
-	for i := 0; i < 100; i++ {
-		bar.Add(1)
-		time.Sleep(10 * time.Millisecond)
-	}
-}
+package main
+
+import (
+	"time"
+
+	"github.com/schollz/progressbar"
+)
+
+func main() {
+	bar := progressbar.New(100)
+	bar.Reset()
+	for i := 0; i < 100; i++ {
+		bar.Add(1)
+		time.Sleep(10 * time.Millisecond)
+	}
+}

progressbar.go

@@ -1,91 +1,110 @@
-package progressbar
-
-import (
-	"fmt"
-	"io"
-	"os"
-	"strings"
-	"sync"
-	"time"
-)
-
-// ProgressBar is a thread-safe, simple
-// progress bar
-type ProgressBar struct {
-	Max               int // max number of the counter
-	Size              int // size of the saucer
-	currentNum        int
-	currentPercent    int
-	lastPercent       int
-	currentSaucerSize int
-
-	lastShown time.Time
-	startTime time.Time
-	w         io.Writer
-
-	// symbols
-	symbolFinished string
-	symbolLeft     string
-	leftBookend    string
-	rightBookend   string
-	sync.RWMutex
-}
-
-// New returns a new ProgressBar
-// with the specified maximum
-func New(max int) *ProgressBar {
-	p := new(ProgressBar)
-	p.Lock()
-	defer p.Unlock()
-	p.Max = max
-	p.Size = 40
-	p.symbolFinished = "█"
-	p.symbolLeft = " "
-	p.leftBookend = "|"
-	p.rightBookend = "|"
-	p.w = os.Stdout
-	p.lastShown = time.Now()
-	p.startTime = time.Now()
-	return p
-}
-
-// Add a certain amount to the progress bar
-func (p *ProgressBar) Add(num int) error {
-	p.Lock()
-	p.currentNum += num
-	percent := float64(p.currentNum) / float64(p.Max)
-	p.currentSaucerSize = int(percent * float64(p.Size))
-	p.currentPercent = int(percent * 100)
-	updateBar := p.currentPercent != p.lastPercent
-	p.lastPercent = p.currentPercent
-	p.Unlock()
-	if updateBar {
-		return p.Show()
-	}
-	return nil
-}
-
-// Show will print the current progress bar
-func (p *ProgressBar) Show() error {
-	p.RLock()
-	defer p.RUnlock()
-	secondsLeft := time.Since(p.startTime).Seconds() / float64(p.currentNum) * (float64(p.Max) - float64(p.currentNum))
-	s := fmt.Sprintf("\r%3d%% %s%s%s%s [%s:%s]",
-		p.currentPercent,
-		p.leftBookend,
-		strings.Repeat(p.symbolFinished, p.currentSaucerSize),
-		strings.Repeat(p.symbolLeft, p.Size-p.currentSaucerSize),
-		p.rightBookend,
-		time.Since(p.startTime).Round(time.Second).String(),
-		(time.Duration(secondsLeft) * time.Second).String(),
-	)
-
-	_, err := io.WriteString(p.w, s)
-	if err != nil {
-		return err
-	}
-	if f, ok := p.w.(*os.File); ok {
-		f.Sync()
-	}
-	return nil
-}
+package progressbar
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"sync"
+	"time"
+)
+
+// ProgressBar is a thread-safe, simple
+// progress bar
+type ProgressBar struct {
+	Max               int // max number of the counter
+	Size              int // size of the saucer
+	currentNum        int
+	currentPercent    int
+	lastPercent       int
+	currentSaucerSize int
+
+	lastShown time.Time
+	startTime time.Time
+	w         io.Writer
+
+	// symbols
+	symbolFinished string
+	symbolLeft     string
+	leftBookend    string
+	rightBookend   string
+	sync.RWMutex
+}
+
+// New returns a new ProgressBar
+// with the specified maximum
+func New(max int) *ProgressBar {
+	p := new(ProgressBar)
+	p.Lock()
+	defer p.Unlock()
+	p.Max = max
+	p.Size = 40
+	p.symbolFinished = "█"
+	p.symbolLeft = " "
+	p.leftBookend = "|"
+	p.rightBookend = "|"
+	p.w = os.Stdout
+	p.lastShown = time.Now()
+	p.startTime = time.Now()
+	return p
+}
+
+// Reset will reset the clock
+func (p *ProgressBar) Reset() {
+	p.Lock()
+	defer p.Unlock()
+	p.lastShown = time.Now()
+	p.startTime = time.Now()
+}
+
+// Set the max of the progress bar
+func (p *ProgressBar) Set(num int) {
+	p.Lock()
+	defer p.Unlock()
+	p.Max = num
+}
+
+// Add a certain amount to the progress bar
+func (p *ProgressBar) Add(num int) error {
+	p.Lock()
+	p.currentNum += num
+	percent := float64(p.currentNum) / float64(p.Max)
+	p.currentSaucerSize = int(percent * float64(p.Size))
+	p.currentPercent = int(percent * 100)
+	updateBar := p.currentPercent != p.lastPercent && p.currentPercent > 0
+	p.lastPercent = p.currentPercent
+	p.Unlock()
+	if updateBar {
+		return p.Show()
+	}
+	return nil
+}
+
+// Show will print the current progress bar
+func (p *ProgressBar) Show() error {
+	p.RLock()
+	defer p.RUnlock()
+	if p.currentNum > p.Max {
+		return errors.New("current number exceeds max")
+	}
+	secondsLeft := time.Since(p.startTime).Seconds() / float64(p.currentNum) * (float64(p.Max) - float64(p.currentNum))
+	s := fmt.Sprintf("\r%3d%% %s%s%s%s [%s:%s]            ",
+		p.currentPercent,
+		p.leftBookend,
+		strings.Repeat(p.symbolFinished, p.currentSaucerSize),
+		strings.Repeat(p.symbolLeft, p.Size-p.currentSaucerSize),
+		p.rightBookend,
+		time.Since(p.startTime).Round(time.Second).String(),
+		(time.Duration(secondsLeft) * time.Second).String(),
+	)
+
+	_, err := io.WriteString(p.w, s)
+	if err != nil {
+		return err
+	}
+	if f, ok := p.w.(*os.File); ok {
+		f.Sync()
+	}
+	return nil
+}

progressbar_test.go

@@ -1,9 +1,9 @@
-package progressbar
-
-func ExampleBar() {
-	bar := New(10)
-	bar.Add(1)
-
-	// Output:
-	// 10% |████                                    | [0s:0s]
-}
+package progressbar
+
+func ExampleBar() {
+	bar := New(10)
+	bar.Add(1)
+
+	// Output:
+	// 10% |████                                    | [0s:0s]
+}