curl: How to limit size of GET?

Question

I want to retrieve the first 10k bytes from a URL with curl (using PHP in my case). Is there a way to specify this? I thought CURLOPT_BUFFERSIZE would do this, but it just appears to determine the size of a buffer that is reused until all of the content is retrieved.

Answer 1

This is how i do it in c++

int offset = 0;
int size = 10*1024;

char range[256];
curl_slist_s *pHeaders = NULL;
snprintf(range, 256, "Range: bytes=%d-%d", offset, offset+size-1);

pHeaders = curl_slist_append(pHeaders, range);
curl_easy_setopt(pCurlHandle, CURLOPT_HTTPHEADER, pHeaders);

curl_slist_free_all(pHeaders);
pHeaders = NULL;

Edit: Just found out you meant in php. Ill see if i can find out how to port it.

Think this should work in php:

$offset = 0;
$size = 10*1024;

$a = $offset;
$b = $offset + $size-1;

curl_easy_setopt(curlHandle, CURLOPT_HTTPHEADER, array("Range: bytes=$a-$b") );

Answer 2

CURLOPT_RANGE appears to not work in PHP although it's there. At least it didn't have an impact when I tried to use it and a google search will reveal many messages of the same.

Answer 3

If you use fread instead of curl, although I prefer curl, you can specify the size of the data you want to receive, for example:

$fp = @fopen($url, "r") ;

$data = "" ;
if($fp) {
    while (!feof($fp)) {
        $data .= fread($fp, $size) ;
}
fclose($fp) ;

where $size is the size you want to read in each loop.

Answer 4

CURLOPT_RANGE does not work for me also. I did a verbose output and found that it uses "Content-Range:" header instead of "Range:" and hence it outputs all of the page. I guess Content-Range: is a new header which is not supported by many servers.