# Functions
AppendToFile appends data to an existing file.
CopyFile copies a file from src to dst.
Exists checks whether a file or directory exists at the given path.
ListFiles returns a list of all files (not directories) in the given directory.
ReadDirFiles reads the contents of all files in a directory and returns them as a map with file names as keys and file content as values.
ReadFile reads the content of a file and returns it as a string.
WriteFile writes data to a file.