add command convert

cmd/sing-box/cmd_convert.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/sagernet/sing-box/common/conf"
+	"github.com/sagernet/sing-box/common/conf/mergers"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+
+	"github.com/spf13/cobra"
+)
+
+var commandConvertOutput string
+var commandConvertOutputFormat string
+
+var commandConvert = &cobra.Command{
+	Use:   "convert",
+	Short: "Convert configuration",
+	Long: `Convert and merge configuration files between different formats.
+
+Note: comments will be lost after conversion.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		err := convert()
+		if err != nil {
+			log.Fatal(err)
+		}
+	},
+	Args: cobra.NoArgs,
+}
+
+func init() {
+	commandConvert.Flags().StringVarP(&commandConvertOutput, "output", "o", "", "output file")
+	commandConvert.Flags().StringVarP(&commandConvertOutputFormat, "output-format", "f", string(mergers.FormatJSON), "output format: json, yaml, toml")
+	mainCommand.AddCommand(commandConvert)
+}
+
+func convert() error {
+	var (
+		configContent []byte
+		err           error
+	)
+	format := mergers.ParseFormat(configFormat)
+	outFormat := mergers.ParseFormat(commandConvertOutputFormat)
+	switch outFormat {
+	case mergers.FormatJSON,
+		mergers.FormatYAML,
+		mergers.FormatTOML:
+		// ok
+	default:
+		return E.New("unsupported output format: ", commandConvertOutputFormat)
+	}
+	if len(configPaths) == 1 && configPaths[0] == "stdin" {
+		configContent, err = conf.ReaderToJSON(os.Stdin, format)
+	} else {
+		configContent, err = conf.FilesToJSON(configPaths, format, configRecursive)
+	}
+	if err != nil {
+		return E.Cause(err, "read config")
+	}
+
+	var options option.Options
+	err = options.UnmarshalJSON(configContent)
+	if err != nil {
+		return E.Cause(err, "decode config")
+	}
+	content, err := conf.Sprint(options, outFormat)
+	if err != nil {
+		return E.Cause(err, "encode config")
+	}
+
+	if commandConvertOutput == "" {
+		os.Stdout.WriteString(content + "\n")
+		return nil
+	}
+
+	output, err := os.Create(commandConvertOutput)
+	if err != nil {
+		return E.Cause(err, "open output")
+	}
+	_, err = output.WriteString(content)
+	output.Close()
+	if err != nil {
+		return E.Cause(err, "write output")
+	}
+	outputPath, _ := filepath.Abs(commandConvertOutput)
+	os.Stderr.WriteString(outputPath + "\n")
+	return nil
+}