curl / libcurl / API / curl_easy_setopt / CURLOPT_RANGE

CURLOPT_RANGE explained

Name

CURLOPT_RANGE - byte range to request

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RANGE, char *range);

Description

Pass a char pointer as parameter, which should contain the specified range you want to retrieve. It should be in the format "X-Y", where either X or Y may be left out and X and Y are byte indexes.

HTTP transfers also support several intervals, separated with commas as in "X-Y,N-M". Using this kind of multiple intervals causes the HTTP server to send the response document in pieces (using standard MIME separation techniques). Unfortunately, the HTTP standard (RFC 7233 section 3.1) allows servers to ignore range requests so even when you set CURLOPT_RANGE for a request, you may end up getting the full response sent back.

For RTSP, the formatting of a range should follow RFC 2326 Section 12.29. For RTSP, byte ranges are not permitted. Instead, ranges should be given in npt, utc, or smpte formats.

For HTTP PUT uploads this option should not be used, since it may conflict with other options.

Using this option multiple times makes the last set string override the previous ones. Set it to NULL to disable its use again.

The application does not have to keep the string around after setting this option.

Default

NULL

Protocols

This functionality affects file, ftp, http, rtsp and sftp

Example

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
 
    /* get the first 200 bytes */
    curl_easy_setopt(curl, CURLOPT_RANGE, "0-199");
 
    /* Perform the request */
    curl_easy_perform(curl);
  }
}

History

FILE since 7.18.0, RTSP since 7.20.0

Availability

Added in curl 7.1

Return value

Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient heap space.