How to Check the Existence of Files on Remote Servers from URLs?

Checking Existence of Files from URLs

Determining the existence of a file hosted on a remote server can be a common requirement. While the often-used functions is_file() and file_exists() may not suffice in this scenario, there's an alternative approach that leverages PHP's get_headers function.

By utilizing get_headers, you can retrieve HTTP response headers for the specified URL. These headers provide information about the file's availability and status. Specifically, you need to examine the value of the $result[0] element. If it includes "200 OK," it implies that the file is present on the server.

To facilitate this check, you can employ a custom function like this:

function UR_exists($url){
   $headers=get_headers($url);
   return stripos($headers[0],"200 OK")?true:false;
}

This function returns true if the HTTP response contains "200 OK" and false otherwise.

To test the existence of a URL, you can utilize the function as shown in the following example:

if(UR_exists("http://www.amazingjokes.com/"))
   echo "This page exists";
else
   echo "This page does not exist";

This approach provides a straightforward and efficient method to determine the presence of files from remote URLs without the need for additional dependencies like CURL, which could introduce unnecessary overhead.

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