curl / libcurl / API / curl_easy_setopt / CURLOPT_TIMEOUT

CURLOPT_TIMEOUT explained

Name

CURLOPT_TIMEOUT - maximum time the transfer is allowed to complete

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TIMEOUT, long timeout);

Description

Pass a long as parameter containing timeout - the maximum time in seconds that you allow the entire transfer operation to take. The whole thing, from start to end. Normally, name lookups can take a considerable time and limiting operations risk aborting perfectly normal operations.

CURLOPT_TIMEOUT_MS is the same function but set in milliseconds.

If both CURLOPT_TIMEOUT and CURLOPT_TIMEOUT_MS are set, the value set last is used.

Since this option puts a hard limit on how long time a request is allowed to take, it has limited use in dynamic use cases with varying transfer times. That is especially apparent when using the multi interface, which may queue the transfer, and that time is included. You are advised to explore CURLOPT_LOW_SPEED_LIMIT, CURLOPT_LOW_SPEED_TIME or using CURLOPT_PROGRESSFUNCTION to implement your own timeout logic.

The connection timeout set with CURLOPT_CONNECTTIMEOUT is included in this general all-covering timeout.

With CURLOPT_CONNECTTIMEOUT set to 3 and CURLOPT_TIMEOUT set to 5, the operation can never last longer than 5 seconds.

With CURLOPT_CONNECTTIMEOUT set to 4 and CURLOPT_TIMEOUT set to 2, the operation can never last longer than 2 seconds.

This option may cause libcurl to use the SIGALRM signal to timeout system calls on builds not using asynch DNS. In Unix-like systems, this might cause signals to be used unless CURLOPT_NOSIGNAL is set.

Default

0 (zero) which means it never times out during transfer.

Protocols

This functionality affects all supported protocols

Example

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
 
    /* complete within 20 seconds */
    curl_easy_setopt(curl, CURLOPT_TIMEOUT, 20L);
 
    curl_easy_perform(curl);
  }
}

Availability

Added in curl 7.1

Return value

Returns CURLE_OK. Returns CURLE_BAD_FUNCTION_ARGUMENT if set to a negative value or a value that when converted to milliseconds is too large.