CURLOPT_SEEKDATA explained

Name

CURLOPT_SEEKDATA - pointer passed to the seek callback

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SEEKDATA, void *pointer);

Description

Data pointer to pass to the seek callback function. If you use the CURLOPT_SEEKFUNCTION option, this is the pointer you get as input.

Default

If you do not set this, NULL is passed to the callback.

Protocols

This functionality affects ftp, http and sftp

Example

#include <unistd.h> /* for lseek() */
 
struct data {
  int our_fd;
};
 
static int seek_cb(void *clientp, curl_off_t offset, int origin)
{
  struct data *d = (struct data *)clientp;
  lseek(d->our_fd, offset, origin);
  return CURL_SEEKFUNC_OK;
}
 
int main(void)
{
  struct data seek_data;
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_SEEKFUNCTION, seek_cb);
    curl_easy_setopt(curl, CURLOPT_SEEKDATA, &seek_data);
  }
}

Availability

Added in curl 7.18.0