curl_multi_setopt(3) Library Functions Manual curl_multi_setopt(3)

curl_multi_setopt - set options for a curl multi handle

#include <curl/curl.h>
CURLMcode curl_multi_setopt(CURLM *multi, CURLMoption option, parameter);

curl_multi_setopt(3) is used to tell a libcurl multi handle how to behave. By using the appropriate options to curl_multi_setopt(3), you can change libcurl's behavior when using that multi handle. All options are set with the option followed by the parameter. That parameter can be a long, a function pointer, an object pointer or a curl_off_t type, depending on what the specific option expects. Read this manual carefully as bad input values may cause libcurl to behave badly. You can only set one option in each function call.

deprecated See CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3)
deprecated See CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3)
Size of connection cache. See CURLMOPT_MAXCONNECTS(3)
Max concurrent streams for http2. See CURLMOPT_MAX_CONCURRENT_STREAMS(3)
Max number of connections to a single host. See CURLMOPT_MAX_HOST_CONNECTIONS(3)
deprecated. See CURLMOPT_MAX_PIPELINE_LENGTH(3)
Max simultaneously open connections. See CURLMOPT_MAX_TOTAL_CONNECTIONS(3)
Enable HTTP multiplexing. See CURLMOPT_PIPELINING(3)
deprecated. See CURLMOPT_PIPELINING_SERVER_BL(3)
deprecated. See CURLMOPT_PIPELINING_SITE_BL(3)
Pointer to pass to push callback. See CURLMOPT_PUSHDATA(3)
Callback that approves or denies server pushes. See CURLMOPT_PUSHFUNCTION(3)
Custom pointer passed to the socket callback. See CURLMOPT_SOCKETDATA(3)
Callback informed about what to wait for. See CURLMOPT_SOCKETFUNCTION(3)
Custom pointer to pass to timer callback. See CURLMOPT_TIMERDATA(3)
Callback to receive timeout values. See CURLMOPT_TIMERFUNCTION(3)

This functionality affects all supported protocols

#define MAX_PARALLEL 45
int main(void)
{
  CURLM *multi;
  /* Limit the amount of simultaneous connections curl should allow: */
  curl_multi_setopt(multi, CURLMOPT_MAXCONNECTS, (long)MAX_PARALLEL);
}

Added in curl 7.15.4

The standard CURLMcode for multi interface error codes. Note that it returns a CURLM_UNKNOWN_OPTION if you try setting an option that this version of libcurl does not know of.

curl_multi_cleanup(3), curl_multi_info_read(3), curl_multi_init(3), curl_multi_socket(3)

2024-11-07 libcurl