How Can I Verify a URL's Existence in PHP?

Verifying URL Existence Using PHP

Determining the existence of a URL is a common requirement for web-based applications. In PHP, there are several approaches to accomplish this.

get_headers() Method

One method is to utilize the get_headers() function. This function retrieves a list of HTTP response headers for a specified URL. If the URL exists and returns a non-404 status code, the function will return an array of header information. The following code sample demonstrates the usage of get_headers():

$file = 'http://www.example.com/somefile.jpg';
$file_headers = @get_headers($file);
if(!$file_headers || $file_headers[0] == 'HTTP/1.1 404 Not Found') {
    $exists = false;
}
else {
    $exists = true;
}

curl_init() Function

Another approach is to employ the curl_init() function. This function opens an HTTP session for a specific URL and returns a handle. If the handle is non-false, it indicates that the URL exists. Here's an example using curl_init():

function url_exists($url) {
    return curl_init($url) !== false;
}

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