PHP: Want fsockopen to retrieve portion only of remote xml file - php

Question

I need to retrieve a small amount of data from a very large remote XML file that I access via http. I only need a portion of the file at the beginning, but the files I am accessing can often be so large that downloading them all will cause a timeout. It seems like it should be possible with fsockopen to pull only as much as needed before closing the connection, but nothing I have tried has worked.
Below is a simplified version of what I have been trying. Can anyone tell me what I need to do differently?
<?php
$k = 0;
function socketopen($funcsite, $funcheader){
$fp = fsockopen ($funcsite, 80, $errno, $errstr, 5);
$buffer = NULL;
if ($fp) {
fwrite($fp, "GET " . $funcheader . " HTTP/1.0\r\nHost: " . $funcsite. "\r\n\r\n");
while (!feof($fp)) {
$buffer = fgets($fp, 4096);
echo $buffer;
if($k == 200){
break;
}
$k++;
}
fclose ($fp);
} else {
print "No Response:";
}
return ( html_entity_decode($buffer));
}
$site = "www.remotesite.com";
$header = "/bigdatafile.xml";
$data = socketopen($site, $header);
?>
This works fine, but always opens and downloads the entire remote file. (I actually use a different conditional than the if($k = x), but that shouldn't matter).
Any help greatly appreciated. -Jim

Answer 1

Any reason not to use file_get_contents() instead?
$buffer = html_entity_decode(file_get_contents('http://www.remotesite.com/bigdatafile.xml', 0, null, $offsetBytes, $maxlenBytes));
You just need to specify $offsetBytes and $maxlenBytes.
Try this:
set_time_limit(0);
echo $buffer = html_entity_decode(file_get_contents('http://www.remotesite.com/bigdatafile.xml', 0, null, 1024, 4096));

Answer 2

with this code you could download the entire rss
if (!$xml = simplexml_load_file("http://remotesite.com/bigrss.rss))
{
throw new RuntimeException('Unable to load or parse feed');
}
else
{
file_put_contents($xml,'mybigrss.rss');
}
but if you want to get just some parts then do the following;
$limit = 512000; // set here a limit
$sourceData = fread($s_handle,$limit);
// your code ect..
Or with eof
$source='';
while (!feof($s_handle))
$source.=fread($s_handle,1024); // set limit