These are special characters that are recognised by the shell. Here are some that you will use often:
![\begin{commandlist} % latex2html id marker 3469\par \item[\tt *] This is a \lq wi... ...n. If it fails, then a helpful error message is printed. \par \end{commandlist}](/help/doc/images/img28.png)
Your initial use of shell metacharacters will be for simple interactive use, as in the above examples. Remember, however, that Unix shells are fully-featured programming languages and that all these constructs can be used to powerful effect in shell programs or scripts. See the following section on Shell Scripts.