Are there any existing PHP functions or libraries that can assist in accessing and manipulating files in the filesystem?

To access and manipulate files in the filesystem using PHP, you can utilize built-in functions like `file_get_contents`, `file_put_contents`, `fopen`, `fwrite`, `fclose`, `unlink`, `rename`, `copy`, `mkdir`, `rmdir`, and more. Additionally, PHP provides the `SplFileObject` class for object-oriented file manipulation. These functions and classes allow you to read, write, create, delete, and perform various operations on files within the filesystem.

// Example: Reading a file using file_get_contents
$fileContents = file_get_contents('example.txt');
echo $fileContents;

// Example: Writing to a file using file_put_contents
$data = 'Hello, World!';
file_put_contents('example.txt', $data);

// Example: Using SplFileObject for file manipulation
$file = new SplFileObject('example.txt', 'r+');
while (!$file->eof()) {
    echo $file->fgets();
}
$file = null;