cli: add multipleStrings type

Will be used for --exclude.

cli_args.go

@@ -39,6 +39,18 @@ type argContainer struct {
 	_forceOwner *fuse.Owner
 }
 
+type multipleStrings []string
+
+func (s *multipleStrings) String() string {
+	s2 := []string(*s)
+	return fmt.Sprint(s2)
+}
+
+func (s *multipleStrings) Set(val string) error {
+	*s = append(*s, val)
+	return nil
+}
+
 var flagSet *flag.FlagSet
 
 // prefixOArgs transform options passed via "-o foo,bar" into regular options

cli_args_test.go

@@ -77,3 +77,14 @@ func TestPrefixOArgs(t *testing.T) {
 		}
 	}
 }
+
+func TestStringSlice(t *testing.T) {
+	var s multipleStrings
+	s.Set("foo")
+	s.Set("bar")
+	want := "[foo bar]"
+	have := s.String()
+	if want != have {
+		t.Errorf("Wrong string representation: want=%q have=%q", want, have)
+	}
+}