cmd: add a standalone version command to print version, as an alternative of --version (#2229)

cmd/main.go

@@ -58,6 +58,7 @@ func Main(args []string) error {
 			cmdFsck(),
 			cmdDump(),
 			cmdLoad(),
+			cmdVersion(),
 			cmdStatus(),
 			cmdStats(),
 			cmdProfile(),

cmd/version.go

@@ -0,0 +1,35 @@
+/*
+ * JuiceFS, Copyright 2022 Juicedata, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"fmt"
+
+	"github.com/urfave/cli/v2"
+)
+
+func cmdVersion() *cli.Command {
+	return &cli.Command{
+		Name:     "version",
+		Category: "ADMIN",
+		Action: func(c *cli.Context) error {
+			fmt.Printf("%s version %s\n", c.App.Name, c.App.Version)
+			return nil
+		},
+		Usage: "Show version",
+	}
+}