1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLOPT_TCP_NODELAY
5Section: 3
6Source: libcurl
7See-also:
8  - CURLOPT_BUFFERSIZE (3)
9  - CURLOPT_SOCKOPTFUNCTION (3)
10  - CURLOPT_TCP_KEEPALIVE (3)
11Protocol:
12  - All
13---
14
15# NAME
16
17CURLOPT_TCP_NODELAY - the TCP_NODELAY option
18
19# SYNOPSIS
20
21~~~c
22#include <curl/curl.h>
23
24CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_NODELAY, long nodelay);
25~~~
26
27# DESCRIPTION
28
29Pass a long specifying whether the *TCP_NODELAY* option is to be set or
30cleared (1L = set, 0 = clear). The option is set by default. This has no
31effect after the connection has been established.
32
33Setting this option to 1L disables the Nagle algorithm on connections created
34using this handle. The purpose of this algorithm is to minimize the number of
35small packets on the network (where "small packets" means TCP segments less
36than the Maximum Segment Size for the network).
37
38Maximizing the amount of data sent per TCP segment is good because it
39amortizes the overhead of the send. However, in some cases small segments may
40need to be sent without delay. This is less efficient than sending larger
41amounts of data at a time, and can contribute to congestion on the network if
42overdone.
43
44# DEFAULT
45
461
47
48# EXAMPLE
49
50~~~c
51int main(void)
52{
53  CURL *curl = curl_easy_init();
54  if(curl) {
55    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
56    /* leave Nagle enabled */
57    curl_easy_setopt(curl, CURLOPT_TCP_NODELAY, 0);
58    curl_easy_perform(curl);
59  }
60}
61~~~
62
63# AVAILABILITY
64
65Always. The default was changed to 1 from 0 in 7.50.2.
66
67# RETURN VALUE
68
69Returns CURLE_OK
70