cmd: implement --stats-one-line-date and --stats-one-line-date-format

docs/content/docs.md

@@ -800,6 +800,18 @@ section](#logging) for more info on log levels.
 When this is specified, rclone condenses the stats into a single line
 showing the most important stats only.
 
+### --stats-one-line-date ###
+
+When this is specified, rclone enables the single-line stats and prepends
+the display with a date string. The default is `2006/01/02 15:04:05 - `
+
+### --stats-one-line-date-format ###
+
+When this is specified, rclone enables the single-line stats and prepends
+the display with a user-supplied date string. The date string MUST be
+enclosed in quotes. Follow [golang specs](https://golang.org/pkg/time/#Time.Format) for
+date formatting syntax.
+
 ### --stats-unit=bits|bytes ###
 
 By default, data transfer rates will be printed in bytes/second.

fs/accounting/stats.go

@@ -216,6 +216,7 @@ func (s *StatsInfo) String() string {
 		currentSize  = s.bytes
 		buf          = &bytes.Buffer{}
 		xfrchkString = ""
+		dateString   = ""
 	)
 
 	if !fs.Config.StatsOneLine {
@@ -231,9 +232,14 @@ func (s *StatsInfo) String() string {
 		if len(xfrchk) > 0 {
 			xfrchkString = fmt.Sprintf(" (%s)", strings.Join(xfrchk, ", "))
 		}
+		if fs.Config.StatsOneLineDate {
+			t := time.Now()
+			dateString = t.Format(fs.Config.StatsOneLineDateFormat) // Including the separator so people can customize it
+		}
 	}
 
-	_, _ = fmt.Fprintf(buf, "%10s / %s, %s, %s, ETA %s%s",
+	_, _ = fmt.Fprintf(buf, "%s%10s / %s, %s, %s, ETA %s%s",
+		dateString,
 		fs.SizeSuffix(s.bytes),
 		fs.SizeSuffix(totalSize).Unit("Bytes"),
 		percent(s.bytes, totalSize),

fs/config.go

@@ -85,6 +85,8 @@ type ConfigInfo struct {
 	MaxTransfer            SizeSuffix
 	MaxBacklog             int
 	StatsOneLine           bool
+	StatsOneLineDate       bool   // If we want a date prefix at all
+	StatsOneLineDateFormat string // If we want to customize the prefix
 	Progress               bool
 	Cookie                 bool
 	UseMmap                bool
@@ -120,6 +122,8 @@ func NewConfig() *ConfigInfo {
 	c.TPSLimitBurst = 1
 	c.MaxTransfer = -1
 	c.MaxBacklog = 10000
+	// We do not want to set the default here. We use this variable being empty as part of the fall-through of options.
+	//	c.StatsOneLineDateFormat = "2006/01/02 15:04:05 - "
 
 	return c
 }

fs/config/configflags/configflags.go

@@ -87,6 +87,8 @@ func AddFlags(flagSet *pflag.FlagSet) {
 	flags.FVarP(flagSet, &fs.Config.MaxTransfer, "max-transfer", "", "Maximum size of data to transfer.")
 	flags.IntVarP(flagSet, &fs.Config.MaxBacklog, "max-backlog", "", fs.Config.MaxBacklog, "Maximum number of objects in sync or check backlog.")
 	flags.BoolVarP(flagSet, &fs.Config.StatsOneLine, "stats-one-line", "", fs.Config.StatsOneLine, "Make the stats fit on one line.")
+	flags.BoolVarP(flagSet, &fs.Config.StatsOneLineDate, "stats-one-line-date", "", fs.Config.StatsOneLineDate, "Enables --stats-one-line and add current date/time prefix.")
+	flags.StringVarP(flagSet, &fs.Config.StatsOneLineDateFormat, "stats-one-line-date-format", "", fs.Config.StatsOneLineDateFormat, "Enables --stats-one-line-date and uses custom formatted date. Enclose date string in double quotes (\"). See https://golang.org/pkg/time/#Time.Format")
 	flags.BoolVarP(flagSet, &fs.Config.Progress, "progress", "P", fs.Config.Progress, "Show progress during transfer.")
 	flags.BoolVarP(flagSet, &fs.Config.Cookie, "use-cookies", "", fs.Config.Cookie, "Enable session cookiejar.")
 	flags.BoolVarP(flagSet, &fs.Config.UseMmap, "use-mmap", "", fs.Config.UseMmap, "Use mmap allocator (see docs).")
@@ -149,6 +151,15 @@ func SetFlags() {
 		log.Fatalf(`Can only use --suffix with --backup-dir.`)
 	}
 
+	switch {
+	case len(fs.Config.StatsOneLineDateFormat) > 0:
+		fs.Config.StatsOneLineDate = true
+		fs.Config.StatsOneLine = true
+	case fs.Config.StatsOneLineDate:
+		fs.Config.StatsOneLineDateFormat = "2006/01/02 15:04:05 - "
+		fs.Config.StatsOneLine = true
+	}
+
 	if bindAddr != "" {
 		addrs, err := net.LookupIP(bindAddr)
 		if err != nil {