diff --git a/core/sys.go b/core/sys.go
index 1236962..c5f90e7 100644
--- a/core/sys.go
+++ b/core/sys.go
@@ -36,7 +36,7 @@ func Daemon() {
 		panic(err)
 	}
 	logs.Info(sillyGirl.Get("name", "傻妞") + "以静默形式运行")
-	WriteToFile(pidf, (fmt.Sprintf("%d", proc.Process.Pid)))
+	os.WriteFile(pidf, []byte(fmt.Sprintf("%d", proc.Process.Pid)), 0o644)
 	os.Exit(0)
 }
 
diff --git a/core/test.go b/core/test.go
index 8b47b8b..b94979c 100644
--- a/core/test.go
+++ b/core/test.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io/ioutil"
+	"os"
 	"os/exec"
 	"strings"
 	"time"
@@ -250,7 +251,7 @@ Alias=sillyGirl.service`
 					s.Reply(data)
 					return nil
 				}
-				WriteToFile("/usr/lib/systemd/system/sillyGirl.service", (service))
+				os.WriteFile("/usr/lib/systemd/system/sillyGirl.service", []byte(service), 0o644)
 				exec.Command("systemctl", "disable", string(sillyGirl)).Output()
 				exec.Command("systemctl", "enable", string(sillyGirl)).Output()
 				return "电脑重启后生效。"
diff --git a/core/utils.go b/core/utils.go
deleted file mode 100644
index 4d57e23..0000000
--- a/core/utils.go
+++ /dev/null
@@ -1,18 +0,0 @@
-package core
-
-import (
-	"fmt"
-	"os"
-)
-
-func WriteToFile(fileName string, content string) error {
-	f, err := os.OpenFile(fileName, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
-	if err != nil {
-		fmt.Println("file create failed. err: " + err.Error())
-	} else {
-		n, _ := f.Seek(0, os.SEEK_END)
-		_, err = f.WriteAt([]byte(content), n)
-		defer f.Close()
-	}
-	return err
-}