Add time.Duration flag type

context.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"strconv"
 	"strings"
+	"time"
 )
 
 // Context is a type that is passed through to
@@ -29,6 +30,11 @@ func (c *Context) Int(name string) int {
 	return lookupInt(name, c.flagSet)
 }
 
+// Looks up the value of a local time.Duration flag, returns 0 if no time.Duration flag exists
+func (c *Context) Duration(name string) time.Duration {
+	return lookupDuration(name, c.flagSet)
+}
+
 // Looks up the value of a local float64 flag, returns 0 if no float64 flag exists
 func (c *Context) Float64(name string) float64 {
 	return lookupFloat64(name, c.flagSet)
@@ -69,6 +75,11 @@ func (c *Context) GlobalInt(name string) int {
 	return lookupInt(name, c.globalSet)
 }
 
+// Looks up the value of a global time.Duration flag, returns 0 if no time.Duration flag exists
+func (c *Context) GlobalDuration(name string) time.Duration {
+	return lookupDuration(name, c.globalSet)
+}
+
 // Looks up the value of a global bool flag, returns false if no bool flag exists
 func (c *Context) GlobalBool(name string) bool {
 	return lookupBool(name, c.globalSet)
@@ -174,6 +185,18 @@ func lookupInt(name string, set *flag.FlagSet) int {
 	return 0
 }
 
+func lookupDuration(name string, set *flag.FlagSet) time.Duration {
+	f := set.Lookup(name)
+	if f != nil {
+		val, err := time.ParseDuration(f.Value.String())
+		if err == nil {
+			return val
+		}
+	}
+
+	return 0
+}
+
 func lookupFloat64(name string, set *flag.FlagSet) float64 {
 	f := set.Lookup(name)
 	if f != nil {