diff --git a/cd.sh b/cd.sh
index cd52fec..babce94 100644
--- a/cd.sh
+++ b/cd.sh
@@ -32,6 +32,16 @@ function step {
     fi
 }
 
+function write {
+local file="${1}"
+local text="${2}"
+    if [ "${file}" ] ; then
+        echo -n "${text}" \
+        > "${file}" \
+        || exit
+    fi
+}
+
 step "set name servers"
 for server in "${CD_DNS_SERVERS[@]}" ; do
     echo "nameserver ${server}" \