Return zets as JSON if --json or -j is passed

cmd/titles.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"log"
 	"strings"
 
 	"github.com/spf13/cobra"
@@ -13,12 +14,28 @@ var titlesCmd = &cobra.Command{
 	Use:     "titles",
 	Aliases: []string{"t"},
 	Short:   "Print IDs and titles of zettels",
-	Long:    `Print the IDs and titles of all zettels.`,
+	Long: `Print the IDs and titles of all zettels.
+
+If -j or --json is added, the results will be in JSON format.`,
 	Run: func(cmd *cobra.Command, args []string) {
 		zets := lib.GetAllZets()
 
 		result := lib.ParseZetList(zets)
 
-		fmt.Println(strings.Join(result, "\n"))
+		if jsonOutput {
+			json, err := lib.AsJSON(result)
+
+			if err != nil {
+				log.Fatal(err)
+			}
+
+			fmt.Println(json)
+		} else {
+			fmt.Println(strings.Join(result, "\n"))
+		}
 	},
 }
+
+func init() {
+	titlesCmd.Flags().BoolVarP(&jsonOutput, "json", "j", false, "Output results in JSON format")
+}