curl_multi_setopt(3) Library Functions Manual 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 be-
have. 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, de-
pending 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_CONCUR-
RENT_STREAMS(3)
CURLMOPT_MAX_HOST_CONNECTIONS
Max number of connections to a single host. See CURL-
MOPT_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_CON-
NECTIONS(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 CURL-
MOPT_PUSHFUNCTION(3)
CURLMOPT_SOCKETDATA
Custom pointer passed to the socket callback. See CURLMOPT_SOCK-
ETDATA(3)
CURLMOPT_SOCKETFUNCTION
Callback informed about what to wait for. See CURLMOPT_SOCKET-
FUNCTION(3)
CURLMOPT_TIMERDATA
Custom pointer to pass to timer callback. See CURLMOPT_TIMER-
DATA(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)
libcurl 2026-07-12 curl_multi_setopt(3)
Generated by dwww version 1.16 on Sat Oct 3 05:08:37 CEST 2026.