Checks if resource is a file.
Reads entire file into a string.
Checks if resource is a directory.
Reads entire file into an array.
Checks if a file is readable.
Writes a string to a file.
Checks if a file or directory is writable.
Gets the current working directory.
Gets the file’s last access time.
Changes current directory.
Gets the file modification time.
Changes the file group.
Gets the file size (in bytes).
Changes filesystem permissions.