re-order the arguments (#274)

cmd/main.go

@@ -79,7 +79,7 @@ func main() {
 		}
 	}
 
-	err := app.Run(os.Args)
+	err := app.Run(reorderOptions(app, os.Args))
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -160,6 +160,74 @@ func stringContains(s []string, e string) bool {
 	return false
 }
 
+func isFlag(flags []cli.Flag, option string) (bool, bool) {
+	if !strings.HasPrefix(option, "-") {
+		return false, false
+	}
+	// --V or -v work the same
+	option = strings.TrimLeft(option, "-")
+	for _, flag := range flags {
+		_, isBool := flag.(*cli.BoolFlag)
+		for _, name := range flag.Names() {
+			if option == name || strings.HasPrefix(option, name+"=") {
+				return true, !isBool && !strings.Contains(option, "=")
+			}
+		}
+	}
+	return false, false
+}
+
+func reorderOptions(app *cli.App, args []string) []string {
+	var newArgs = []string{args[0]}
+	var others []string
+	globalFlags := append(app.Flags, cli.VersionFlag)
+	for i := 1; i < len(args); i++ {
+		option := args[i]
+		if ok, hasValue := isFlag(globalFlags, option); ok {
+			newArgs = append(newArgs, option)
+			if hasValue {
+				i++
+				newArgs = append(newArgs, args[i])
+			}
+		} else {
+			others = append(others, option)
+		}
+	}
+	// no command
+	if len(others) == 0 {
+		return newArgs
+	}
+	cmdName := others[0]
+	var cmd *cli.Command
+	for _, c := range app.Commands {
+		if c.Name == cmdName {
+			cmd = c
+		}
+	}
+	if cmd == nil {
+		// can't recognize the command, skip it
+		return append(newArgs, others...)
+	}
+
+	newArgs = append(newArgs, cmdName)
+	args, others = others[1:], nil
+	// -h is valid for all the commands
+	cmdFlags := append(cmd.Flags, cli.HelpFlag)
+	for i := 0; i < len(args); i++ {
+		option := args[i]
+		if ok, hasValue := isFlag(cmdFlags, option); ok {
+			newArgs = append(newArgs, option)
+			if hasValue {
+				i++
+				newArgs = append(newArgs, args[i])
+			}
+		} else {
+			others = append(others, option)
+		}
+	}
+	return append(newArgs, others...)
+}
+
 func setLoggerLevel(c *cli.Context) {
 	if c.Bool("trace") {
 		utils.SetLogLevel(logrus.TraceLevel)

cmd/main_test.go

+/*
+ * JuiceFS, Copyright (C) 2020 Juicedata, Inc.
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package main
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/urfave/cli/v2"
+)
+
+func TestArgsOrder(t *testing.T) {
+	var app = &cli.App{
+		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:    "verbose",
+				Aliases: []string{"v"},
+			},
+			&cli.Int64Flag{
+				Name:    "key",
+				Aliases: []string{"k"},
+			},
+		},
+		Commands: []*cli.Command{
+			{
+				Name: "cmd",
+				Flags: []cli.Flag{
+					&cli.Int64Flag{
+						Name: "k2",
+					},
+				},
+			},
+		},
+	}
+
+	var cases = [][]string{
+		{"test", "cmd", "a", "-k2", "v2", "b", "--v"},
+		{"test", "--v", "cmd", "-k2", "v2", "a", "b"},
+		{"test", "cmd", "a", "-k2=v", "--h"},
+		{"test", "cmd", "-k2=v", "--h", "a"},
+	}
+	for i := 0; i < len(cases); i += 2 {
+		oreded := reorderOptions(app, cases[i])
+		if !reflect.DeepEqual(cases[i+1], oreded) {
+			t.Fatalf("expecte %v, but got %v", cases[i+1], oreded)
+		}
+	}
+}