fs: make display of default values of --min-age/--max-age be off - Fixes #2121

fs/parseduration.go

@@ -9,11 +9,22 @@ import (
 // Duration is a time.Duration with some more parsing options
 type Duration time.Duration
 
+// DurationOff is the default value for flags which can be turned off
+const DurationOff = Duration((1 << 63) - 1)
+
 // Turn Duration into a string
 func (d Duration) String() string {
+	if d == DurationOff {
+		return "off"
+	}
 	return time.Duration(d).String()
 }
 
+// IsSet returns if the duration is != DurationOff
+func (d Duration) IsSet() bool {
+	return d != DurationOff
+}
+
 // We use time conventions
 var ageSuffixes = []struct {
 	Suffix     string
@@ -36,6 +47,10 @@ var ageSuffixes = []struct {
 func ParseDuration(age string) (time.Duration, error) {
 	var period float64
 
+	if age == "off" {
+		return time.Duration(DurationOff), nil
+	}
+
 	for _, ageSuffix := range ageSuffixes {
 		if strings.HasSuffix(age, ageSuffix.Suffix) {
 			numberString := age[:len(age)-len(ageSuffix.Suffix)]
@@ -64,5 +79,5 @@ func (d *Duration) Set(s string) error {
 
 // Type of the value
 func (d Duration) Type() string {
-	return "time.Duration"
+	return "duration"
 }