CURLOPT_UPLOAD_BUFFERSIZE(3)

1CURLOPT_UPLOAD_BUFFERSIZE(3)        libcurl       CURLOPT_UPLOAD_BUFFERSIZE(3)
2
3
4

NAME

6       CURLOPT_UPLOAD_BUFFERSIZE - upload buffer size
7

SYNOPSIS

9       #include <curl/curl.h>
10
11       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPLOAD_BUFFERSIZE, long size);
12

DESCRIPTION

14       Pass  a  long  specifying your preferred size (in bytes) for the upload
15       buffer in libcurl. It makes libcurl uses  a  larger  buffer  that  gets
16       passed  to  the next layer in the stack to get sent off. In some setups
17       and for some protocols, there's a huge performance benefit of having  a
18       larger upload buffer.
19
20       This  is just treated as a request, not an order. You cannot be guaran‐
21       teed to actually get the given size.
22
23       The upload buffer size is by default 64 kilobytes. The  maximum  buffer
24       size  allowed to be set is 2 megabytes. The minimum buffer size allowed
25       to be set is 16 kilobytes.
26
27       Since curl 7.61.1 the upload buffer is allocated on-demand - so if  the
28       handle  is  not  used  for upload, this buffer will not be allocated at
29       all.
30
31       DO NOT set this option on a handle that is currently used for an active
32       transfer as that may lead to unintended consequences.
33

DEFAULT

35       65536 bytes
36

PROTOCOLS

38       All
39

EXAMPLE

41       CURL *curl = curl_easy_init();
42       if(curl) {
43         curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/foo.bin");
44
45         /* ask libcurl to allocate a larger upload buffer */
46         curl_easy_setopt(curl, CURLOPT_UPLOAD_BUFFERSIZE, 120000L);
47
48         ret = curl_easy_perform(curl);
49
50         curl_easy_cleanup(curl);
51       }
52

AVAILABILITY

54       Added in 7.62.0.
55

RETURN VALUE

57       Returns  CURLE_OK  if the option is supported, and CURLE_UNKNOWN_OPTION
58       if not.
59