rpm2cpio, as its name suggest, takes an RPM package file and convert it into cpio archive. The cpio is a binary file archiver and is a stream of files and directories in a single archive.
rpm2cpio takes only only one argument. The interesting part is its optional.
It is the name of the package file to be converted. Under no filename specified o n the command line, rpm2cpio will simply read from standard input and convert that to a cpio archive.
Let's download the subversion RPM (as an example) and see how rpm2cpio can be used to display the files.