rclone/cmd/progress.go
Nick Craig-Wood e09a4ff019 cmd: Make --progress work in git bash on Windows - fixes #3531
This detects the presence of a VT100 terminal by using the TERM
environment variable and switches to using VT100 codes directly under
windows if it is found.

This makes --progress work correctly with git bash.
2019-09-13 15:24:47 +01:00

149 lines
3 KiB
Go

// Show the dynamic progress bar
package cmd
import (
"bytes"
"fmt"
"os"
"strings"
"sync"
"time"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/accounting"
"github.com/rclone/rclone/fs/log"
"golang.org/x/crypto/ssh/terminal"
)
const (
// interval between progress prints
defaultProgressInterval = 500 * time.Millisecond
// time format for logging
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() {
// Intercept the log calls if not logging to file or syslog
fs.LogPrint = func(level fs.LogLevel, text string) {
printProgress(fmt.Sprintf("%s %-6s: %s", time.Now().Format(logTimeFormat), level, text))
}
}
var wg sync.WaitGroup
wg.Add(1)
go func() {
defer wg.Done()
progressInterval := defaultProgressInterval
if ShowStats() && *statsInterval > 0 {
progressInterval = *statsInterval
}
ticker := time.NewTicker(progressInterval)
for {
select {
case <-ticker.C:
printProgress("")
case <-stopStats:
ticker.Stop()
printProgress("")
fs.LogPrint = oldLogPrint
fmt.Println("")
return
}
}
}()
return func() {
close(stopStats)
wg.Wait()
}
}
// 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
progressMu sync.Mutex
)
// printProgress prints the progress with an optional log
func printProgress(logMessage string) {
progressMu.Lock()
defer progressMu.Unlock()
var buf bytes.Buffer
w, h, err := terminal.GetSize(int(os.Stdout.Fd()))
if err != nil {
w, h = 80, 25
}
_ = h
stats := strings.TrimSpace(accounting.GlobalStats().String())
logMessage = strings.TrimSpace(logMessage)
out := func(s string) {
buf.WriteString(s)
}
if logMessage != "" {
out("\n")
out(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(moveUp)
}
out(eraseLine)
out(moveToStartOfLine)
if logMessage != "" {
out(eraseLine)
out(logMessage + "\n")
}
fixedLines := strings.Split(stats, "\n")
nlines = len(fixedLines)
for i, line := range fixedLines {
if len(line) > w {
line = line[:w]
}
out(line)
if i != nlines-1 {
out("\n")
}
}
writeToTerminal(buf.Bytes())
}