22. cp command copy files from one location to another. If the destination is an existing file, then the file is overwritten; if the destination is an existing directory, the file is copied into the directory (the directory is not overwritten).
66. cmp file1 file2 - Compares two files, reporting all discrepancies. Similar to the diff command, though the output format differs.
67. wc filename --- tells you how many lines, words, and characters there are in a file
68. whoami --- returns your username. Sounds useless, but isn't. You may need to find out who it is who forgot to log out somewhere, and make sure *you* have logged out.