fputs() expects parameter 2 to be string, array given in code example
Example: fwrite() expects parameter 2 to be string, array given
//If you explicit need to put array in file you can do it with this
fwrite($handle, print_r($result, true));
//or you can convert it to json, like this
fwrite($handle, json_encode($result));
//And later when you read the file you can just undo the action with
//json_decode($your_file_content)