validate.go: Modify the output mode

Signed-off-by: zhouhao <[email protected]>

Author: zhouhao

cmd/oci-image-tool/validate.go

@@ -49,16 +49,17 @@ func validateHandler(context *cli.Context) error {
 	}
 
 	v = validateCmd{
-		typ:  context.String("type"),
-		refs: context.StringSlice("ref"),
+		stdout: log.New(os.Stdout, "", 0),
+		typ:    context.String("type"),
+		refs:   context.StringSlice("ref"),
 	}
 
 	var errs []string
 	for _, arg := range context.Args() {
 		err := validatePath(arg)
 
 		if err == nil {
-			fmt.Printf("%s: OK\n", arg)
+			v.stdout.Printf("%s: OK\n", arg)
 			continue
 		}
 
@@ -77,7 +78,7 @@ func validateHandler(context *cli.Context) error {
 	if len(errs) > 0 {
 		return fmt.Errorf("%d errors detected: \n%s", len(errs), strings.Join(errs, "\n"))
 	}
-	fmt.Println("Validation succeeded")
+	v.stdout.Println("Validation succeeded")
 	return nil
 }
 
@@ -93,10 +94,6 @@ func validatePath(name string) error {
 		}
 	}
 
-	if v.stdout == nil {
-		v.stdout = log.New(os.Stdout, "oci-image-tool: ", 0)
-	}
-
 	switch typ {
 	case image.TypeImageLayout:
 		return image.ValidateLayout(name, v.refs, v.stdout)
@@ -105,7 +102,7 @@ func validatePath(name string) error {
 	}
 
 	if len(v.refs) != 0 {
-		fmt.Printf("WARNING: type %q does not support refs, which are only appropriate if type is image or imageLayout.\n", typ)
+		v.stdout.Printf("WARNING: type %q does not support refs, which are only appropriate if type is image or imageLayout.\n", typ)
 	}
 
 	f, err := os.Open(name)

image/image.go

@@ -115,7 +115,7 @@ func validate(w walker, refs []string, out *log.Logger) error {
 			}
 
 			if len(index.Manifests) == 0 {
-				fmt.Println("warning: no manifests found")
+				out.Println("warning: no manifests found")
 				return nil
 			}