repo/core/curl/files/curl_multi_setopt.3

.\" generated by cd2nroff 0.1 from curl_multi_setopt.md
.TH curl_multi_setopt 3 "2024-07-29" libcurl
.SH NAME
curl_multi_setopt \- set options for a curl multi handle
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *multi, CURLMoption option, parameter);
.fi
.SH DESCRIPTION
\fIcurl_multi_setopt(3)\fP is used to tell a libcurl multi handle how to behave. By
using the appropriate options to \fIcurl_multi_setopt(3)\fP, you can change
libcurl\(aqs behavior when using that multi handle. All options are set with the
\fIoption\fP followed by the \fIparameter\fP. That parameter can be a \fBlong\fP, a
\fBfunction pointer\fP, an \fBobject pointer\fP or a \fBcurl_off_t\fP 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.
.SH OPTIONS
.IP CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE
\fBdeprecated\fP See \fICURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3)\fP
.IP CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE
\fBdeprecated\fP See \fICURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3)\fP
.IP CURLMOPT_MAXCONNECTS
Size of connection cache. See \fICURLMOPT_MAXCONNECTS(3)\fP
.IP CURLMOPT_MAX_CONCURRENT_STREAMS
Max concurrent streams for http2. See \fICURLMOPT_MAX_CONCURRENT_STREAMS(3)\fP
.IP CURLMOPT_MAX_HOST_CONNECTIONS
Max number of connections to a single host. See
\fICURLMOPT_MAX_HOST_CONNECTIONS(3)\fP
.IP CURLMOPT_MAX_PIPELINE_LENGTH
\fBdeprecated\fP. See \fICURLMOPT_MAX_PIPELINE_LENGTH(3)\fP
.IP CURLMOPT_MAX_TOTAL_CONNECTIONS
Max simultaneously open connections. See \fICURLMOPT_MAX_TOTAL_CONNECTIONS(3)\fP
.IP CURLMOPT_PIPELINING
Enable HTTP multiplexing. See \fICURLMOPT_PIPELINING(3)\fP
.IP CURLMOPT_PIPELINING_SERVER_BL
\fBdeprecated\fP. See \fICURLMOPT_PIPELINING_SERVER_BL(3)\fP
.IP CURLMOPT_PIPELINING_SITE_BL
\fBdeprecated\fP. See \fICURLMOPT_PIPELINING_SITE_BL(3)\fP
.IP CURLMOPT_PUSHDATA
Pointer to pass to push callback. See \fICURLMOPT_PUSHDATA(3)\fP
.IP CURLMOPT_PUSHFUNCTION
Callback that approves or denies server pushes. See \fICURLMOPT_PUSHFUNCTION(3)\fP
.IP CURLMOPT_SOCKETDATA
Custom pointer passed to the socket callback. See \fICURLMOPT_SOCKETDATA(3)\fP
.IP CURLMOPT_SOCKETFUNCTION
Callback informed about what to wait for. See \fICURLMOPT_SOCKETFUNCTION(3)\fP
.IP CURLMOPT_TIMERDATA
Custom pointer to pass to timer callback. See \fICURLMOPT_TIMERDATA(3)\fP
.IP CURLMOPT_TIMERFUNCTION
Callback to receive timeout values. See \fICURLMOPT_TIMERFUNCTION(3)\fP
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf

#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);
}
.fi
.SH AVAILABILITY
Added in curl 7.15.4
.SH RETURN VALUE
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.
.SH SEE ALSO
.BR curl_multi_cleanup (3),
.BR curl_multi_info_read (3),
.BR curl_multi_init (3),
.BR curl_multi_socket (3)