.CPIO File Extension
What is a CPIO file?
File archive created in the Unix CPIO (Copy In, Copy Out) format, an uncompressed file container format used for grouping files together; similar to a .TAR archive and can be compressed into a .CPGZ file using Gzip compression.
The "ditto" BSD utility can be used to create and extract CPIO files. For example, ditto -c creates a CPIO archive. The Java Commons Compress API can also be used for creating and extracting CPIO archives.