CURLOPT_SEEKDATA(3)

CURLOPT_SEEKDATA3

Pointer passed to the seek callback

Usage

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

Overview

Data pointer to pass to the seek callback function. If you use the CURLOPT_SEEKFUNCTION(3) 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

Examples

#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);
  }
}

Return value

Releases

7 releases since Debian 8 (Jessie); the text changed 6 times.

  1. 8
  2. 9
  3. 10
  4. 11
  5. 12
  6. 13
  7. Arch

Availability

Added in curl 7.18.0

From curl 8.23.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.