Change error message format

file_result.go

@@ -16,12 +16,12 @@ func (r fileResult) String(verbose bool) string {
 	ss := make([]string, 0, len(r.urlResults))
 
 	if r.err != nil {
-		ss = append(ss, "\t"+color.RedString(r.err.Error()))
+		ss = append(ss, indent(color.RedString(r.err.Error())))
 	}
 
 	for _, r := range r.urlResults {
 		if r.err != nil || verbose {
-			ss = append(ss, "\t"+r.String())
+			ss = append(ss, indent(r.String()))
 		}
 	}
 

url_result.go

@@ -12,5 +12,5 @@ func (r urlResult) String() string {
 		return color.GreenString("OK") + "\t" + r.url
 	}
 
-	return color.RedString("ERROR") + "\t" + r.url + "\t" + color.YellowString(r.err.Error())
+	return color.RedString("ERROR") + "\t" + r.url + "\n\t" + color.YellowString(r.err.Error())
 }

utils.go

@@ -3,6 +3,8 @@ package main
 import (
 	"fmt"
 	"os"
+
+	"github.com/kr/text"
 )
 
 func stringSetToSlice(s2b map[string]bool) []string {
@@ -18,3 +20,7 @@ func stringSetToSlice(s2b map[string]bool) []string {
 func printToStderr(xs ...interface{}) {
 	fmt.Fprintln(os.Stderr, xs...)
 }
+
+func indent(s string) string {
+	return text.Indent(s, "\t")
+}