URL的等效is_file（）函数？

Question

What is the best way to check if a given url points to a valid file (i.e. not return a 404/301/etc.)? I've got a script that will load certain .js files on a page, but I need a way to verify each URL it receives points to a valid file.

I'm still poking around the PHP manual to see which file functions (if any) will actually work with remote URLs. I'll edit my post as I find more details, but if anyone has already been down this path feel free to chime in.

Answer 1

The file_get_contents is a bit overshooting the purpose as it is enough to have the HTTP header to make the decision, so you'll need to use curl to do so:

<?php
// create a new cURL resource
$ch = curl_init();

// set URL and other appropriate options
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);

// grab URL and pass it to the browser
curl_exec($ch);

// close cURL resource, and free up system resources
curl_close($ch);
?>