Lookup _ rather than - for env

argset.go

@@ -42,6 +42,26 @@ func (as *ArgSet) Get(key string) *Arg {
 	return nil
 }
 
+func (as *ArgSet) GetInt(key string) int {
+	a := as.Get(key)
+	return a.GetInt()
+}
+
+func (as *ArgSet) GetBool(key string) bool {
+	a := as.Get(key)
+	return a.GetBool()
+}
+
+func (as *ArgSet) GetDuration(key string) time.Duration {
+	a := as.Get(key)
+	return a.GetDuration()
+}
+
+func (as *ArgSet) GetString(key string) string {
+	a := as.Get(key)
+	return a.GetString()
+}
+
 func (as *ArgSet) Parse() error {
 	if as.parsed {
 		return nil
@@ -78,6 +98,7 @@ func (as *ArgSet) setValueFromDefaults() error {
 func (as *ArgSet) setValueFromEnv() error {
 	for i := range as.args {
 		key := as.args[i].Env
+		key = strings.ReplaceAll(key, "-", "_")
 		if v, ok := os.LookupEnv(key); ok {
 			if err := as.args[i].Set(v); err != nil {
 				return err