The command cpio

unpacks a cpio file: cpio -iv <cpio_file> 

display the contents of a cpio file: cpio -itv <cpio_file>

The command rpm2cpio

unpacks all files of an RPM package: rpm2cpio RPM_file | cpio -idv 

unpack all files of a RPM package and select only the needed files: rpm2cpio RPM_file | cpio -idv <individual_file>

Example:

rpm2cpio openssl-0.9.7a-2.i386.rpm | cpio -idv ./lib/libssl.so.0.9.7a ./lib/libcrypto.so.0.9.7a

rpm2cpio RPM_file | cpio -it egrep <individual_file> 

rpm2cpio urlgrabber-0.2-1.src.rpm | cpio -it egrep <*spec>