Are there any best practices for handling HTTP paths when checking for file existence in PHP?

When checking for file existence in PHP using HTTP paths, it is important to sanitize and validate the input to prevent security vulnerabilities such as directory traversal attacks. One best practice is to use the realpath() function to resolve the full path of the file and then check if the file exists using file_exists(). 

$path = $_GET['path']; // Assuming the HTTP path is passed as a query parameter
$fullPath = realpath($_SERVER['DOCUMENT_ROOT'] . '/' . $path);

if ($fullPath && file_exists($fullPath)) {
    // File exists, do something
    echo "File exists at path: " . $fullPath;
} else {
    // File does not exist or invalid path
    echo "File does not exist or invalid path";
}

Keywords

HTTP paths file existence PHP handling best practices

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