diff --git a/sh/util.sh b/sh/util.sh
index 4dd81bf..cbcd67a 100644
--- a/sh/util.sh
+++ b/sh/util.sh
@@ -1,3 +1,18 @@
+rwx_file_append() {
+	local file="${1}"
+	local text="${2}"
+	if [ -n "${file}" ]; then
+		printf "%s" "${text}" >>"${file}"
+	fi
+}
+
+rwx_file_empty() {
+	local file="${1}"
+	if [ -n "${file}" ]; then
+		rwx_file_write "${file}" ""
+	fi
+}
+
 rwx_file_write() {
 	local file="${1}"
 	local text="${2}"