PHP: Default cURL timeout value

Question

What is the default PHP cURL timeout value? Can I obtain the value from coding?

Answer 1

It depends on which timeout setting you're talking about.

cURL offers various options specific to connection timeout settings. Some of these options have a set limit, while others allow transfers to take an indefinite amount of time. In order to understand which values have default settings and which do not, you need to look at libcurl's curl_easy_setopt() function: http://curl.haxx.se/libcurl/c/curl_easy_setopt.html

libcurl lists the following connection timeout specific settings:

• CURLOPT_FTP_RESPONSE_TIMEOUT: No default (indefinite)
• CURLOPT_TIMEOUT: No default (indefinite)
• CURLOPT_TIMEOUT_MS: No default (indefinite)
• CURLOPT_CONNECTTIMEOUT: Defaults to 300 seconds
• CURLOPT_CONNECTTIMEOUT_MS: No default
• CURLOPT_ACCEPTTIMEOUT_MS: Defaults to 60000 ms

The PHP source code does not override any of the above default settings: https://github.com/php/php-src/blob/master/ext/curl/interface.c. The only somewhat related parameter that the PHP bindings override is CURLOPT_DNS_CACHE_TIMEOUT, changing the default value from 60 seconds to 120 seconds: https://github.com/php/php-src/blob/a0e3ca1c986681d0136ce4550359ecee2826a80c/ext/curl/interface.c#L1926

One of the other answers stated that PHP will set CURLOPT_TIMEOUT to the value specified in the default_socket_timeout ini setting. I was not able to find anything in the PHP source code to back up this claim, and I was unable to trigger a cURL timeout by downloading a very large file with a default_socket_timeout setting of 1 second.