Are there any specific PHP functions or methods that are recommended for handling file operations in this scenario?

When handling file operations in PHP, it is recommended to use functions like `file_get_contents()` and `file_put_contents()` for reading and writing files, respectively. These functions simplify the process of working with files by abstracting away some of the lower-level details. Additionally, using functions like `file_exists()` and `is_readable()` can help ensure that the file operations are performed safely.

// Check if file exists and is readable
$filename = 'example.txt';

if (file_exists($filename) && is_readable($filename)) {
    // Read file contents
    $content = file_get_contents($filename);
    
    // Modify file contents
    $newContent = strtoupper($content);
    
    // Write modified contents back to file
    file_put_contents($filename, $newContent);
    
    echo "File operation successful.";
} else {
    echo "File does not exist or is not readable.";
}