xref: /curl/docs/libcurl/curl_multi_setopt.md (revision 5a488251)
1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: curl_multi_setopt
5Section: 3
6Source: libcurl
7See-also:
8  - curl_multi_cleanup (3)
9  - curl_multi_info_read (3)
10  - curl_multi_init (3)
11  - curl_multi_socket (3)
12Protocol:
13  - All
14Added-in: 7.15.4
15---
16
17# NAME
18
19curl_multi_setopt - set options for a curl multi handle
20
21# SYNOPSIS
22
23~~~c
24#include <curl/curl.h>
25
26CURLMcode curl_multi_setopt(CURLM *multi, CURLMoption option, parameter);
27~~~
28
29# DESCRIPTION
30
31curl_multi_setopt(3) is used to tell a libcurl multi handle how to behave. By
32using the appropriate options to curl_multi_setopt(3), you can change
33libcurl's behavior when using that multi handle. All options are set with the
34*option* followed by the *parameter*. That parameter can be a **long**, a
35**function pointer**, an **object pointer** or a **curl_off_t** type,
36depending on what the specific option expects. Read this manual carefully as
37bad input values may cause libcurl to behave badly. You can only set one
38option in each function call.
39
40# OPTIONS
41
42## CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE
43
44**deprecated** See CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3)
45
46## CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE
47
48**deprecated** See CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3)
49
50## CURLMOPT_MAXCONNECTS
51
52Size of connection cache. See CURLMOPT_MAXCONNECTS(3)
53
54## CURLMOPT_MAX_CONCURRENT_STREAMS
55
56Max concurrent streams for http2. See CURLMOPT_MAX_CONCURRENT_STREAMS(3)
57
58## CURLMOPT_MAX_HOST_CONNECTIONS
59
60Max number of connections to a single host. See
61CURLMOPT_MAX_HOST_CONNECTIONS(3)
62
63## CURLMOPT_MAX_PIPELINE_LENGTH
64
65**deprecated**. See CURLMOPT_MAX_PIPELINE_LENGTH(3)
66
67## CURLMOPT_MAX_TOTAL_CONNECTIONS
68
69Max simultaneously open connections. See CURLMOPT_MAX_TOTAL_CONNECTIONS(3)
70
71## CURLMOPT_PIPELINING
72
73Enable HTTP multiplexing. See CURLMOPT_PIPELINING(3)
74
75## CURLMOPT_PIPELINING_SERVER_BL
76
77**deprecated**. See CURLMOPT_PIPELINING_SERVER_BL(3)
78
79## CURLMOPT_PIPELINING_SITE_BL
80
81**deprecated**. See CURLMOPT_PIPELINING_SITE_BL(3)
82
83## CURLMOPT_PUSHDATA
84
85Pointer to pass to push callback. See CURLMOPT_PUSHDATA(3)
86
87## CURLMOPT_PUSHFUNCTION
88
89Callback that approves or denies server pushes. See CURLMOPT_PUSHFUNCTION(3)
90
91## CURLMOPT_SOCKETDATA
92
93Custom pointer passed to the socket callback. See CURLMOPT_SOCKETDATA(3)
94
95## CURLMOPT_SOCKETFUNCTION
96
97Callback informed about what to wait for. See CURLMOPT_SOCKETFUNCTION(3)
98
99## CURLMOPT_TIMERDATA
100
101Custom pointer to pass to timer callback. See CURLMOPT_TIMERDATA(3)
102
103## CURLMOPT_TIMERFUNCTION
104
105Callback to receive timeout values. See CURLMOPT_TIMERFUNCTION(3)
106
107# %PROTOCOLS%
108
109# EXAMPLE
110
111~~~c
112
113#define MAX_PARALLEL 45
114
115int main(void)
116{
117  CURLM *multi;
118  /* Limit the amount of simultaneous connections curl should allow: */
119  curl_multi_setopt(multi, CURLMOPT_MAXCONNECTS, (long)MAX_PARALLEL);
120}
121~~~
122
123# %AVAILABILITY%
124
125# RETURN VALUE
126
127The standard CURLMcode for multi interface error codes. Note that it returns a
128CURLM_UNKNOWN_OPTION if you try setting an option that this version of libcurl
129does not know of.
130