Add api command

cmd/sing-box/cmd_api_version.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"os"
+
+	"github.com/sagernet/sing-box/daemon"
+	F "github.com/sagernet/sing/common/format"
+
+	"github.com/spf13/cobra"
+	"google.golang.org/protobuf/types/known/emptypb"
+)
+
+var commandAPIVersion = &cobra.Command{
+	Use:   "version",
+	Short: "Print the API service version",
+	Args:  cobra.NoArgs,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		return runAPIVersion()
+	},
+}
+
+func init() {
+	commandAPIRoot.AddCommand(commandAPIVersion)
+}
+
+func runAPIVersion() error {
+	clientConn, client, err := createAPIClient()
+	if err != nil {
+		return err
+	}
+	defer clientConn.Close()
+	version, err := client.GetVersion(globalCtx, &emptypb.Empty{})
+	if err != nil {
+		return err
+	}
+	if version.GetApiVersion() != daemon.APIVersion {
+		writeStderrLine(F.ToString("warning: server API version ", version.GetApiVersion(), ", client ", daemon.APIVersion))
+	}
+	os.Stdout.WriteString(version.GetVersion() + "\n")
+	return nil
+}