em đang dùng curl để craw data web. rất thường hay bị lỗi load hoài không dùng được, chỉ get nội dung của 3 -4 web thôi mà nó load hơn 5 phút không dùng.  

vào php.ini thấy max_execution_time là 30s, mà ko thấy hiệu quả,  

The maximum execution time is not affected by system calls, stream operations etc. Please see the set_time_limit() function for more details. The set_time_limit() function and the configuration directive max_execution_time only affect the execution time of the script itself. Any time spent on activity that happens outside the execution of the script such as system calls using system(), stream operations, database queries, etc. is not included when determining the maximum time that the script has been running. This is not true on Windows where the measured time is real. 

vậy h để làm sao để giới hạn lại chỉ 30s chay script thôi  

CURLOPT_TIMEOUT The maximum number of seconds to allow cURL functions to execute.