CURLOPT_UPLOAD_BUFFERSIZE(3)                          curl_easy_setopt options

NAME
       CURLOPT_UPLOAD_BUFFERSIZE - set preferred upload buffer size

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPLOAD_BUFFERSIZE, long
       size);

DESCRIPTION
       Pass a long specifying your preferred size (in bytes) for the upload
       buffer in libcurl. It makes libcurl uses a larger buffer that gets
       passed to the next layer in the stack to get sent off. In some setups
       and for some protocols, there's a huge performance benefit of having a
       larger upload buffer.

       This is just treated as a request, not an order. You cannot be
       guaranteed to actually get the given size.

       The upload buffer size is by default 64 kilobytes. The maximum buffer
       size allowed to be set is 2 megabytes. The minimum buffer size allowed
       to be set is 16 kilobytes.

       Since curl 7.61.1 the upload buffer is allocated on-demand - so if the
       handle isn't used for upload, this buffer will not be allocated at all.

       DO NOT set this option on a handle that is currently used for an active
       transfer as that may lead to unintended consequences.

DEFAULT
       64 kB

PROTOCOLS
       All

EXAMPLE
       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/foo.bin");

         /* ask libcurl to allocate a larger upload buffer */
         curl_easy_setopt(curl, CURLOPT_UPLOAD_BUFFERSIZE, 120000L);

         ret = curl_easy_perform(curl);

         curl_easy_cleanup(curl);
       }

AVAILABILITY
       Added in 7.62.0.

RETURN VALUE
       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION
       if not.

SEE ALSO
       CURLOPT_BUFFERSIZE(3), CURLOPT_READFUNCTION(3),

libcurl 7.77.0                    May 6, 2021     CURLOPT_UPLOAD_BUFFERSIZE(3)