DOKK / manpages / debian 11 / libcurl4-doc / CURLOPT_RESUME_FROM.3.en
CURLOPT_RESUME_FROM(3) curl_easy_setopt options CURLOPT_RESUME_FROM(3)

CURLOPT_RESUME_FROM - set a point to resume transfer from

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESUME_FROM, long from);

Pass a long as parameter. It contains the offset in number of bytes that you want the transfer to start from. Set this option to 0 to make the transfer start from the beginning (effectively disabling resume). For FTP, set this option to -1 to make the transfer start from the end of the target file (useful to continue an interrupted upload).

When doing uploads with FTP, the resume position is where in the local/source file libcurl should try to resume the upload from and it will then append the source file to the remote target file.

If you need to resume a transfer beyond the 2GB limit, use CURLOPT_RESUME_FROM_LARGE(3) instead.

0, not used

HTTP, FTP, SFTP, FILE

CURL *curl = curl_easy_init();
if(curl) {

curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com");
/* resume upload at byte index 200 */
curl_easy_setopt(curl, CURLOPT_RESUME_FROM, 200L);
/* ask for upload */
curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
/* set total data amount to expect */
curl_easy_setopt(curl, CURLOPT_INFILESIZE, size_of_file);
/* Perform the request */
curl_easy_perform(curl); }

Always

Returns CURLE_OK

CURLOPT_RESUME_FROM_LARGE(3), CURLOPT_RANGE(3), CURLOPT_INFILESIZE(3),

November 4, 2020 libcurl 7.74.0