🎨 complete SMS login function

utils/gen_validate_code.go

@@ -0,0 +1,20 @@
+package utils
+
+import (
+	"fmt"
+	"math/rand"
+	"strings"
+	"time"
+)
+
+func GenValidateCode(width int) string {
+	numeric := [10]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
+	r := len(numeric)
+	rand.New(rand.NewSource(time.Now().UnixNano()))
+
+	var sb strings.Builder
+	for i := 0; i < width; i++ {
+		fmt.Fprintf(&sb, "%d", numeric[rand.Intn(r)])
+	}
+	return sb.String()
+}