CURLOPT_UPLOAD_BUFFERSIZE - upload buffer size
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_UPLOAD_BUFFERSIZE, long size);
curl_easy_setopt options CURLOPT_UPLOAD_BUFFERSIZE(3) 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 guaran- teed 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. ATTRIBUTES See attributes(7) for descriptions of the following attributes: +---------------+------------------+ |ATTRIBUTE TYPE | ATTRIBUTE VALUE | +---------------+------------------+ |Availability | web/curl | +---------------+------------------+ |Stability | Uncommitted | +---------------+------------------+ SEE ALSO CURLOPT_BUFFERSIZE(3), CURLOPT_READFUNCTION(3), NOTES Source code for open source software components in Oracle Solaris can be found at https://www.oracle.com/downloads/opensource/solaris-source- code-downloads.html. This software was built from source available at https://github.com/oracle/solaris-userland. The original community source was downloaded from https://curl.se/down- load/curl-7.83.1.tar.bz2. Further information about this software can be found on the open source community website at http://curl.haxx.se/. libcurl 7.83.1 November 26, 2021 CURLOPT_UPLOAD_BUFFERSIZE(3)