解析PHP 使用curl提交json格式数据

$ch = curl_init('http://api.local/rest/users');
curl_set($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_set($ch, CURLOPT_POSTFIELDS,$data_string);
curl_set($ch, CURLOPT_RETURNTRANSFER,true);
curl_set($ch, CURLOPT_HTTPHEADER, array(
    'Content-Type: application/json',
    'Content-Length: ' . strlen($data_string))
);

$result = curl_exec($ch);