The listing below shows an excerpt from the central header file which is used to enable or disable Crusher features during compiles. Compression and decompression processes can be canceled by setting a flag during any callback message. At that point, you can change its name, destination path, or set a flag to skip the file. Yes, and it's very easy. Just make a few changes to those routines, taking care to follow their documented behavior, and everything else will fall into place.
Crusher is very simple and intuitive to use.
You're probably already familiar with many of its features just by using one of the popular stand-alone utilities. The listing below shows all that's required to implement full pkzip-style backup, including subdirectory processing and wildcards.