However, it is worth first noting a little history. This new shell provided exciting stuff like job control and a C-like syntax. These two shells sort of define the syntax of subsequent ones. The shell is your interface with the operating system, and most of them are quite powerful, providing a programming facility with variables and control structure like any programming language, as well as other features like job control and command line editing. I will provide some examples using the tcsh shell.
Variables can be either scalar or list .
It is possible to iterate over a list and perform some command. I believe one of the fundamental traits of a good system administrator is the ability to know where to look for answers. Ideally, every command you can use from a shell ought to have a concise and standardized manpage, so that you can quickly get the information you need from it. Life is not so grand though, and many version of Unix have frustrating or even non-existant manual pages. That is a good reason to always stick with online manpages as there is a good chance they match the actual functionality present in a given command.