The UNIX cksum command is used to display the checksum and the size of a file. This command is useful in verifying file integrity over noisy transmission lines. Here's an example of its application.
# cksum firefox-1.0-sparc-sun-solaris2.8.tar
2821005393 55203840 firefox-1.0-sparc-sun-solaris2.8.tar
I saw some email traffic from someone asking for methods of verifying files over noisy lines, so I thought this might be a useful post.