Downloading big files and writing it locally - php

Question

which is the best way to download from php large files without consuming all server's memory?
I could do this (bad code):
$url='http://server/bigfile';
$cont = file_get_contents($url);
file_put_contents('./localfile',$cont);
This example loads entry remote file in $cont and this could exceed memory limit.
Is there a safe function (maybe built-in) to do this (maybe stream_*)?
Thanks

Answer 1

You can use curl and the option CURLOPT_FILE to save the downloaded content directly to a file.
set_time_limit(0);
$fp = fopen ('file', 'w+b');
$ch = curl_init('http://remote_url/file');
curl_setopt($ch, CURLOPT_TIMEOUT, 75);
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_exec($ch);
curl_close($ch);
fclose($fp);

Answer 2

Here is a function I use when downloading large files. It will avoid loading the entire file into the buffer. Instead, it will write to the destination as it receives the bytes.
function download($file_source, $file_target)
{
$rh = fopen($file_source, 'rb');
$wh = fopen($file_target, 'wb');
if (!$rh || !$wh) {
return false;
}
while (!feof($rh)) {
if (fwrite($wh, fread($rh, 1024)) === FALSE) {
return false;
}
}
fclose($rh);
fclose($wh);
return true;
}