tee command (as in a T-splitter in plumbing) takes content from standard input, displays it and writes it to one or more files. It is useful if you need to write things to several files in one go. You have the choice to either overwrite the contents of the file or append new content to the end. tee is very simple and handy if you need something like this. It should be installed on all Linux systems as part of the GNU Coreutils package.