curl / libcurl / API / curl_easy_setopt / CURLOPT_RESUME_FROM_LARGE

CURLOPT_RESUME_FROM_LARGE explained

Name

CURLOPT_RESUME_FROM_LARGE - offset to resume transfer from

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESUME_FROM_LARGE,
                          curl_off_t from);

Description

Pass a curl_off_t 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 appends the source file to the remote target file.

Default

0, not used

Protocols

All

Example

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_off_t resume_position; /* get it somehow */
    curl_off_t file_size; /* get it somehow as well */
 
    curl_easy_setopt(curl, CURLOPT_URL, "ftp://example.com");
 
    /* resuming upload at this position, possibly beyond 2GB */
    curl_easy_setopt(curl, CURLOPT_RESUME_FROM_LARGE, resume_position);
 
    /* ask for upload */
    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
 
    /* set total data amount to expect */
    curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE, file_size);
 
    /* Perform the request */
    curl_easy_perform(curl);
  }
}

Availability

Added in 7.11.0

Return value

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