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* Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
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CURLOPT_SEEKDATA - custom pointer passed to the seek callback #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SEEKDATA, void *pointer); Data pointer to pass to the seek callback function. If you use the CURLOPT_SEEKFUNCTION(3) option, this is the pointer you'll get as input. If you don't set this, NULL is passed to the callback. HTTP, FTP, SFTP

static int seek_cb(void *userp, curl_off_t offset, int origin)
{
 struct data *d = (struct data *)userp;
 lseek(d->our_fd, offset, origin);
 return CURL_SEEKFUNC_OK;
}

{
 struct data seek_data;
 curl_easy_setopt(CURL *handle, CURLOPT_SEEKFUNCTION, seek_cb);
 curl_easy_setopt(CURL *handle, CURLOPT_SEEKDATA, &seek_data);
}

Added in 7.18.0 CURLOPT_STDERR "(3), " CURLOPT_DEBUGFUNCTION "(3), "