This class can be used to process directories recursively. It can traverse directories recursively. The class invokes callback classes to perform any actions the applications need. There are callback classes for several purposes. This class has a main function named exec_on_folder that takes a folder path and loops on its contents recursively. When a file entry (a file or folder) is found the callback function as defined by exec_on_folder_callback interface is called. This can be used to execute anything on a directory tree structure: - You can delete a directory by traversing the tree in postfix traversal. - You can print out the tree in a nice format using the depth of the files - You can put input and get output from the callback function by setting variables in the callback object it is in.