- var_dump: documentation ( source)
- json_last_error_msg: documentation ( source)
- json_encode: documentation ( source)
- fopen: documentation ( source)
<?php
$fp = fopen('php://stdin', 'r');
$json = @json_encode(array('a' => 'foo', 'b' => $fp));
var_dump($json, json_last_error_msg());