CURLOPT_APPEND - append to the remote file

Added in curl 7.17.0

0 (disabled)

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.

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

CURLOPT_APPEND - append to the remote file

This functionality affects ftp and sftp

curl_easy_setopt(3) returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLOPT_DIRLISTONLY(3), CURLOPT_RESUME_FROM(3), CURLOPT_UPLOAD(3) libcurl 2025-06-16 CURLOPT_APPEND(3)

#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_APPEND, long append);