curl_multi_setopt(3)

NAME
curl_multi_setopt - set options for a curl multi handle

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

DESCRIPTION
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.

OPTIONS

CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE
    deprecated See CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3)

CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE
    deprecated See CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3)

CURLMOPT_MAXCONNECTS
    Size of connection cache. See CURLMOPT_MAXCONNECTS(3)

CURLMOPT_MAX_CONCURRENT_STREAMS
    Max concurrent streams for http2. See CURLMOPT_MAX_CONCURRENT_STREAMS(3)

CURLMOPT_MAX_HOST_CONNECTIONS
    Max number of connections to a single host. See CURLMOPT_MAX_HOST_CONNECTIONS(3)

CURLMOPT_MAX_PIPELINE_LENGTH
    deprecated. See CURLMOPT_MAX_PIPELINE_LENGTH(3)

CURLMOPT_MAX_TOTAL_CONNECTIONS
    Max simultaneously open connections. See CURLMOPT_MAX_TOTAL_CONNECTIONS(3)

CURLMOPT_NETWORK_CHANGED
    Signal that the network has changed. See CURLMOPT_NETWORK_CHANGED(3)

CURLMOPT_NOTIFYDATA
    Custom pointer passed to the notify callback. See CURLMOPT_NOTIFYDATA(3)

CURLMOPT_NOTIFYFUNCTION
    Callback that receives notifications. See CURLMOPT_NOTIFYFUNCTION(3)

CURLMOPT_PIPELINING
    Enable HTTP multiplexing. See CURLMOPT_PIPELINING(3)

CURLMOPT_PIPELINING_SERVER_BL
    deprecated. See CURLMOPT_PIPELINING_SERVER_BL(3)

CURLMOPT_PIPELINING_SITE_BL
    deprecated. See CURLMOPT_PIPELINING_SITE_BL(3)

CURLMOPT_PUSHDATA
    Pointer to pass to push callback. See CURLMOPT_PUSHDATA(3)

CURLMOPT_PUSHFUNCTION
    Callback that approves or denies server pushes. See CURLMOPT_PUSHFUNCTION(3)

CURLMOPT_QUICK_EXIT
    Enable a quicker cleanup of the multi handle. See CURLMOPT_QUICK_EXIT(3)

CURLMOPT_RESOLVE_THREADS_MAX
    Max threads used for threaded DNS resolver. See CURLMOPT_RESOLVE_THREADS_MAX(3)

CURLMOPT_SOCKETDATA
    Custom pointer passed to the socket callback. See CURLMOPT_SOCKETDATA(3)

CURLMOPT_SOCKETFUNCTION
    Callback informed about what to wait for. See CURLMOPT_SOCKETFUNCTION(3)

CURLMOPT_TIMERDATA
    Custom pointer to pass to timer callback. See CURLMOPT_TIMERDATA(3)

CURLMOPT_TIMERFUNCTION
    Callback to receive timeout values. See CURLMOPT_TIMERFUNCTION(3)

PROTOCOLS
This functionality affects all supported protocols

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

AVAILABILITY
Added in curl 7.15.4

RETURN VALUE
This function returns a CURLMcode indicating success or error. CURLM_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3). Note that it returns a CURLM_UNKNOWN_OPTION if you try setting an option that this version of libcurl does not know of.

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