lib/terminal: factor from cmd/progress, swap Azure/go-ansiterm for mattn/go-colorable

cmd/progress.go

@@ -5,7 +5,6 @@ package cmd
 import (
 	"bytes"
 	"fmt"
-	"os"
 	"strings"
 	"sync"
 	"time"
@@ -13,7 +12,7 @@ import (
 	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/accounting"
 	"github.com/rclone/rclone/fs/log"
-	"golang.org/x/crypto/ssh/terminal"
+	"github.com/rclone/rclone/lib/terminal"
 )
 
 const (
@@ -23,34 +22,10 @@ const (
 	logTimeFormat = "2006-01-02 15:04:05"
 )
 
-var (
-	initTerminal    func() error
-	writeToTerminal func([]byte)
-)
-
-// Initialise the VT100 terminal
-func initTerminalVT100() error {
-	return nil
-}
-
-// Write to the VT100 terminal
-func writeToTerminalVT100(b []byte) {
-	_, _ = os.Stdout.Write(b)
-}
-
 // startProgress starts the progress bar printing
 //
 // It returns a func which should be called to stop the stats.
 func startProgress() func() {
-	if os.Getenv("TERM") != "" {
-		initTerminal = initTerminalVT100
-		writeToTerminal = writeToTerminalVT100
-	}
-	err := initTerminal()
-	if err != nil {
-		fs.Errorf(nil, "Failed to start progress: %v", err)
-		return func() {}
-	}
 	stopStats := make(chan struct{})
 	oldLogPrint := fs.LogPrint
 	if !log.Redirected() {
@@ -88,13 +63,6 @@ func startProgress() func() {
 	}
 }
 
-// VT100 codes
-const (
-	eraseLine         = "\x1b[2K"
-	moveToStartOfLine = "\x1b[0G"
-	moveUp            = "\x1b[A"
-)
-
 // state for the progress printing
 var (
 	nlines     = 0 // number of lines in the previous stats block
@@ -107,11 +75,7 @@ func printProgress(logMessage string) {
 	defer progressMu.Unlock()
 
 	var buf bytes.Buffer
-	w, h, err := terminal.GetSize(int(os.Stdout.Fd()))
+	w, _ := terminal.GetSize()
-	if err != nil {
-		w, h = 80, 25
-	}
-	_ = h
 	stats := strings.TrimSpace(accounting.GlobalStats().String())
 	logMessage = strings.TrimSpace(logMessage)
 
@@ -121,17 +85,17 @@ func printProgress(logMessage string) {
 
 	if logMessage != "" {
 		out("\n")
-		out(moveUp)
+		out(terminal.MoveUp)
 	}
 	// Move to the start of the block we wrote erasing all the previous lines
 	for i := 0; i < nlines-1; i++ {
-		out(eraseLine)
+		out(terminal.EraseLine)
-		out(moveUp)
+		out(terminal.MoveUp)
 	}
-	out(eraseLine)
+	out(terminal.EraseLine)
-	out(moveToStartOfLine)
+	out(terminal.MoveToStartOfLine)
 	if logMessage != "" {
-		out(eraseLine)
+		out(terminal.EraseLine)
 		out(logMessage + "\n")
 	}
 	fixedLines := strings.Split(stats, "\n")
@@ -145,5 +109,5 @@ func printProgress(logMessage string) {
 			out("\n")
 		}
 	}
-	writeToTerminal(buf.Bytes())
+	terminal.Write(buf.Bytes())
 }

cmd/progress_other.go

@@ -1,9 +0,0 @@
-//+build !windows
-
-package cmd
-
-func init() {
-	// Default terminal is VT100 for non Windows
-	initTerminal = initTerminalVT100
-	writeToTerminal = writeToTerminalVT100
-}

cmd/progress_windows.go

@@ -1,52 +0,0 @@
-//+build windows
-
-package cmd
-
-import (
-	"fmt"
-	"os"
-	"syscall"
-
-	ansiterm "github.com/Azure/go-ansiterm"
-	"github.com/Azure/go-ansiterm/winterm"
-	"github.com/pkg/errors"
-)
-
-var (
-	ansiParser *ansiterm.AnsiParser
-)
-
-func init() {
-	// Default terminal is Windows console for Windows
-	initTerminal = initTerminalWindows
-	writeToTerminal = writeToTerminalWindows
-}
-
-func initTerminalWindows() error {
-	winEventHandler := winterm.CreateWinEventHandler(os.Stdout.Fd(), os.Stdout)
-	if winEventHandler == nil {
-		err := syscall.GetLastError()
-		if err == nil {
-			err = errors.New("initialization failed")
-		}
-		return errors.Wrap(err, "windows terminal")
-	}
-	ansiParser = ansiterm.CreateParser("Ground", winEventHandler)
-	return nil
-}
-
-func writeToTerminalWindows(b []byte) {
-	// Remove all non-ASCII characters until this is fixed
-	// https://github.com/Azure/go-ansiterm/issues/26
-	r := []rune(string(b))
-	for i := range r {
-		if r[i] >= 127 {
-			r[i] = '.'
-		}
-	}
-	b = []byte(string(r))
-	_, err := ansiParser.Parse(b)
-	if err != nil {
-		_, _ = fmt.Fprintf(os.Stderr, "\n*** Error from ANSI parser: %v\n", err)
-	}
-}

lib/terminal/terminal.go

@@ -0,0 +1,111 @@
+// Package terminal provides VT100 terminal codes and a windows
+// implementation of that.
+package terminal
+
+import (
+	"io"
+	"os"
+	"runtime"
+	"sync"
+
+	colorable "github.com/mattn/go-colorable"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+// VT100 codes
+const (
+	EraseLine         = "\x1b[2K"
+	MoveToStartOfLine = "\x1b[1G"
+	MoveUp            = "\x1b[1A"
+
+	Reset      = "\x1b[0m"
+	Bright     = "\x1b[1m"
+	Dim        = "\x1b[2m"
+	Underscore = "\x1b[4m"
+	Blink      = "\x1b[5m"
+	Reverse    = "\x1b[7m"
+	Hidden     = "\x1b[8m"
+
+	BlackFg   = "\x1b[30m"
+	RedFg     = "\x1b[31m"
+	GreenFg   = "\x1b[32m"
+	YellowFg  = "\x1b[33m"
+	BlueFg    = "\x1b[34m"
+	MagentaFg = "\x1b[35m"
+	CyanFg    = "\x1b[36m"
+	WhiteFg   = "\x1b[37m"
+
+	BlackBg   = "\x1b[40m"
+	RedBg     = "\x1b[41m"
+	GreenBg   = "\x1b[42m"
+	YellowBg  = "\x1b[43m"
+	BlueBg    = "\x1b[44m"
+	MagentaBg = "\x1b[45m"
+	CyanBg    = "\x1b[46m"
+	WhiteBg   = "\x1b[47m"
+
+	HiBlackFg   = "\x1b[90m"
+	HiRedFg     = "\x1b[91m"
+	HiGreenFg   = "\x1b[92m"
+	HiYellowFg  = "\x1b[93m"
+	HiBlueFg    = "\x1b[94m"
+	HiMagentaFg = "\x1b[95m"
+	HiCyanFg    = "\x1b[96m"
+	HiWhiteFg   = "\x1b[97m"
+
+	HiBlackBg   = "\x1b[100m"
+	HiRedBg     = "\x1b[101m"
+	HiGreenBg   = "\x1b[102m"
+	HiYellowBg  = "\x1b[103m"
+	HiBlueBg    = "\x1b[104m"
+	HiMagentaBg = "\x1b[105m"
+	HiCyanBg    = "\x1b[106m"
+	HiWhiteBg   = "\x1b[107m"
+)
+
+var (
+	// make sure that start is only called once
+	once sync.Once
+)
+
+// Start the terminal - must be called before use
+func Start() {
+	once.Do(func() {
+		f := os.Stdout
+		if !terminal.IsTerminal(int(f.Fd())) {
+			// If stdout not a tty then remove escape codes
+			Out = colorable.NewNonColorable(f)
+		} else if runtime.GOOS == "windows" && os.Getenv("TERM") != "" {
+			// If TERM is set just use stdout
+			Out = f
+		} else {
+			Out = colorable.NewColorable(f)
+		}
+	})
+}
+
+// WriteString writes the string passed in to the terminal
+func WriteString(s string) {
+	Write([]byte(s))
+}
+
+// GetSize reads the dimensions of the current terminal or returns a
+// sensible default
+func GetSize() (w, h int) {
+	w, h, err := terminal.GetSize(int(os.Stdout.Fd()))
+	if err != nil {
+		w, h = 80, 25
+	}
+	return w, h
+}
+
+// Out is an io.Writer which can be used to write to the terminal
+// eg for use with fmt.Fprintf(terminal.Out, "terminal fun: %d\n", n)
+var Out io.Writer
+
+// Write sends out to the VT100 terminal.
+// It will initialise the terminal if this is the first call.
+func Write(out []byte) {
+	Start()
+	_, _ = Out.Write(out)
+}