printf

tools/append_or_replace

@@ -14,7 +14,7 @@ STRING=$2
 FILE=$3
 
 if ! grep -Pq "$REGEX" "$FILE"; then
-	printf "$STRING\n" >>$FILE
+	printf "%s\n" "$STRING" >>$FILE
 	echo appended
 else
 	sed -i "s|$REGEX|$STRING|g" $FILE