diff --git a/flag.go b/flag.go
index fa81564..b4bfecb 100644
--- a/flag.go
+++ b/flag.go
@@ -752,7 +752,7 @@
 	return strings.Contains(arg, shorthand)
 }
 
-func (f *FlagSet) parseLongArg(s string, args []string) (a []string, err error) {
+func (f *FlagSet) parseLongArg(s string, args []string, fn parseFunc) (a []string, err error) {
 	a = args
 	name := s[2:]
 	if len(name) == 0 || name[0] == '-' || name[0] == '=' {
@@ -786,11 +786,11 @@
 		err = f.failf("flag needs an argument: %s", s)
 		return
 	}
-	err = f.setFlag(flag, value, s)
+	err = fn(flag, value, s)
 	return
 }
 
-func (f *FlagSet) parseSingleShortArg(shorthands string, args []string) (outShorts string, outArgs []string, err error) {
+func (f *FlagSet) parseSingleShortArg(shorthands string, args []string, fn parseFunc) (outShorts string, outArgs []string, err error) {
 	if strings.HasPrefix(shorthands, "test.") {
 		return
 	}
@@ -825,16 +825,16 @@
 		err = f.failf("flag needs an argument: %q in -%s", c, shorthands)
 		return
 	}
-	err = f.setFlag(flag, value, shorthands)
+	err = fn(flag, value, shorthands)
 	return
 }
 
-func (f *FlagSet) parseShortArg(s string, args []string) (a []string, err error) {
+func (f *FlagSet) parseShortArg(s string, args []string, fn parseFunc) (a []string, err error) {
 	a = args
 	shorthands := s[1:]
 
 	for len(shorthands) > 0 {
-		shorthands, a, err = f.parseSingleShortArg(shorthands, args)
+		shorthands, a, err = f.parseSingleShortArg(shorthands, args, fn)
 		if err != nil {
 			return
 		}
@@ -843,7 +843,7 @@
 	return
 }
 
-func (f *FlagSet) parseArgs(args []string) (err error) {
+func (f *FlagSet) parseArgs(args []string, fn parseFunc) (err error) {
 	for len(args) > 0 {
 		s := args[0]
 		args = args[1:]
@@ -863,9 +863,9 @@
 				f.args = append(f.args, args...)
 				break
 			}
-			args, err = f.parseLongArg(s, args)
+			args, err = f.parseLongArg(s, args, fn)
 		} else {
-			args, err = f.parseShortArg(s, args)
+			args, err = f.parseShortArg(s, args, fn)
 		}
 		if err != nil {
 			return
@@ -881,7 +881,41 @@
 func (f *FlagSet) Parse(arguments []string) error {
 	f.parsed = true
 	f.args = make([]string, 0, len(arguments))
-	err := f.parseArgs(arguments)
+
+	assign := func(flag *Flag, value, origArg string) error {
+		return f.setFlag(flag, value, origArg)
+	}
+
+	err := f.parseArgs(arguments, assign)
+	if err != nil {
+		switch f.errorHandling {
+		case ContinueOnError:
+			return err
+		case ExitOnError:
+			os.Exit(2)
+		case PanicOnError:
+			panic(err)
+		}
+	}
+	return nil
+}
+
+type parseFunc func(flag *Flag, value, origArg string) error
+
+// ParseAll parses flag definitions from the argument list, which should not
+// include the command name. The arguments for fn are flag and value. Must be
+// called after all flags in the FlagSet are defined and before flags are
+// accessed by the program. The return value will be ErrHelp if -help was set
+// but not defined.
+func (f *FlagSet) ParseAll(arguments []string, fn func(flag *Flag, value string) error) error {
+	f.parsed = true
+	f.args = make([]string, 0, len(arguments))
+
+	assign := func(flag *Flag, value, origArg string) error {
+		return fn(flag, value)
+	}
+
+	err := f.parseArgs(arguments, assign)
 	if err != nil {
 		switch f.errorHandling {
 		case ContinueOnError:
@@ -907,6 +941,14 @@
 	CommandLine.Parse(os.Args[1:])
 }
 
+// ParseAll parses the command-line flags from os.Args[1:] and called fn for each.
+// The arguments for fn are flag and value. Must be called after all flags are
+// defined and before flags are accessed by the program.
+func ParseAll(fn func(flag *Flag, value string) error) {
+	// Ignore errors; CommandLine is set for ExitOnError.
+	CommandLine.ParseAll(os.Args[1:], fn)
+}
+
 // SetInterspersed sets whether to support interspersed option/non-option arguments.
 func SetInterspersed(interspersed bool) {
 	CommandLine.SetInterspersed(interspersed)
diff --git a/flag_test.go b/flag_test.go
index b294fc7..ad050b3 100644
--- a/flag_test.go
+++ b/flag_test.go
@@ -333,6 +333,59 @@
 	}
 }
 
+func testParseAll(f *FlagSet, t *testing.T) {
+	if f.Parsed() {
+		fmt.Errorf("f.Parse() = true before Parse")
+	}
+	f.BoolP("boola", "a", false, "bool value")
+	f.BoolP("boolb", "b", false, "bool2 value")
+	f.BoolP("boolc", "c", false, "bool3 value")
+	f.BoolP("boold", "d", false, "bool4 value")
+	f.StringP("stringa", "s", "0", "string value")
+	f.StringP("stringz", "z", "0", "string value")
+	f.StringP("stringx", "x", "0", "string value")
+	f.StringP("stringy", "y", "0", "string value")
+	f.Lookup("stringx").NoOptDefVal = "1"
+	args := []string{
+		"-ab",
+		"-cs=xx",
+		"--stringz=something",
+		"-d=true",
+		"-x",
+		"-y",
+		"ee",
+	}
+	want := []string{
+		"boola", "true",
+		"boolb", "true",
+		"boolc", "true",
+		"stringa", "xx",
+		"stringz", "something",
+		"boold", "true",
+		"stringx", "1",
+		"stringy", "ee",
+	}
+	got := []string{}
+	store := func(flag *Flag, value string) error {
+		got = append(got, flag.Name)
+		if len(value) > 0 {
+			got = append(got, value)
+		}
+		return nil
+	}
+	if err := f.ParseAll(args, store); err != nil {
+		t.Errorf("expected no error, got ", err)
+	}
+	if !f.Parsed() {
+		t.Errorf("f.Parse() = false after Parse")
+	}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("f.ParseAll() fail to restore the args")
+		t.Errorf("Got: %v", got)
+		t.Errorf("Want: %v", want)
+	}
+}
+
 func TestShorthand(t *testing.T) {
 	f := NewFlagSet("shorthand", ContinueOnError)
 	if f.Parsed() {
@@ -398,6 +451,11 @@
 	testParse(GetCommandLine(), t)
 }
 
+func TestParseAll(t *testing.T) {
+	ResetForTesting(func() { t.Error("bad parse") })
+	testParseAll(GetCommandLine(), t)
+}
+
 func TestFlagSetParse(t *testing.T) {
 	testParse(NewFlagSet("test", ContinueOnError), t)
 }