What are the differences between using linear methods and regular expressions in PHP for file access control?

When implementing file access control in PHP, using linear methods involves manually checking each file's permissions and attributes, which can be time-consuming and error-prone. On the other hand, regular expressions allow for more flexible and efficient matching of file paths based on patterns, making it easier to control access to multiple files at once.

// Linear method for file access control
$filePath = 'path/to/file.txt';

if (is_readable($filePath) && file_exists($filePath)) {
    // Access file
} else {
    // Deny access
}

// Regular expressions for file access control
$files = glob('path/to/*.txt');

foreach ($files as $file) {
    if (preg_match('/^path\/to\/file\d+\.txt$/', $file)) {
        // Access file
    } else {
        // Deny access
    }
}