CURLOPT_APPEND - Man Page

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_APPEND, long append);

A long parameter set to 1 tells the library to append to the remote file instead of overwrite it. This is only useful when uploading to an FTP site.

0 (disabled)

This functionality affects ftp only

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {

    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com/dir/to/newfile");
    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
    curl_easy_setopt(curl, CURLOPT_APPEND, 1L);

    curl_easy_perform(curl);
  }
}

This option was known as CURLOPT_FTPAPPEND up to 7.16.4

Added in curl 7.17.0

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

CURLOPT_DIRLISTONLY(3), CURLOPT_RESUME_FROM(3), CURLOPT_UPLOAD(3)

curl_easy_setopt(3), libcurl-symbols(3).