NAME

       CURLOPT_UPLOAD_BUFFERSIZE - 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 is  not  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),