art: Move ListOutput under utils

pkg/utils/strings.go

@@ -1,8 +1,13 @@
 package utils
 
 import (
+	"encoding/json"
+	"fmt"
 	"math/rand"
+	"strings"
 	"time"
+
+	"gopkg.in/yaml.v1"
 )
 
 func init() {
@@ -18,3 +23,19 @@ func RandStringRunes(n int) string {
 	}
 	return string(b)
 }
+
+func ListOutput(rels []string, output string) []string {
+	switch strings.ToLower(output) {
+	case "yaml":
+		d, _ := yaml.Marshal(rels)
+		return []string{string(d)}
+	case "json":
+		d, _ := json.Marshal(rels)
+		return []string{string(d)}
+	default:
+		for _, r := range rels {
+			fmt.Println(r)
+		}
+		return rels
+	}
+}