cURL - Open files outside server's root directory - apache

Question

I am wondering, how can I access a file outside the root directory of my server?
For example, /home/username/FILE.mp3
The code i am currently using to open a file is the following:
<?php
$location = "ABSOLUTE-PATH/FILE.mp3";
$ch = curl_init($location);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_FILETIME, true);
$data = curl_exec($ch);
$timestamp = curl_getinfo($ch, CURLINFO_FILETIME);
curl_close($ch);
if ($data === false) {
echo 'CURL Failed';
exit;
}
//Get file size
if (preg_match('/Content-Length: (\d+)/', $data, $matches)) {
$contentLength = (int)$matches[1];
}
$begin = 0;
$end = $contentLength - 1;
if (preg_match('/bytes=\h*(\d+)-(\d*)[\D.*]?/i', $_SERVER['HTTP_RANGE'], $matches))
{
$begin = intval($matches[1]);
if (!empty($matches[2]))
{
$end = intval($matches[2]);
}
}
if (isset($_SERVER['HTTP_RANGE']))
{ header('HTTP/1.1 206 Partial Content'); }
else
{ header('HTTP/1.1 200 OK'); }
header('Accept-Ranges: bytes');
header('Content-Length: ' . $contentLength);
header("Content-Range: bytes $begin-$end/$contentLength");
header('Content-Type: audio/mpeg');
header('Cache-Control: public, must-revalidate, max-age=0');
if ($timestamp != -1) { //otherwise unknown
header("Last-Modified: " . gmdate("D, d M Y H:i:s", $timestamp) . " GMT");
}
ob_clean();
flush();
echo ($data);
exit;
?>
I know as a fact that cURL doesn't work with relative paths and i assume that a file outside the root directory is treated as a relative link.

Answer 1

Why would you use cURL? Typically cURL would be something you would use to communicate with a different server via HTTP. Why not use file, file_get_contents, fopen or similar?