If you are an novice to unix, the following list of command may be useful for you. Or you can read my webpage on unix command.

commonly used unix commands:
  ls             --- list the contents of current working directory
  cat filename   --- show the contents of a file
  mkdir dir-name --- create a sub-directory under current working directory
  cd dir-name    --- change working-directory to dir-name
  cd ..          --- change working-directory to upper level 
                     Note the space between `cd' and '..'.
  pwd            --- show the current working-directory
  joe filename   --- invoke the editor, ``joe''
  passwd         --- change your password
  rm filename    --- remove a file(Note:The file removed can not be recovered.) 
  mv fa fb       --- rename a file from ``fa'' to ``fb''
                     or, if fb is a directory, move fa to the place under fb

How to run your scheme programs? If you have written your code in a file named s.scm, you can run it as follows.

$ cat s.scm                    <----- show the contents of s.scm
(define (square x) (* x x))
$ scheme48                     <----- invoke the interpreter 
Welcome to Scheme 48 1.8 (made by klim on Tue Feb 17 11:32:15 CST 2009)
Copyright (c) 1993-2008 by Richard Kelsey and Jonathan Rees.
Please report bugs to scheme-48-bugs@s48.org.
Get more information at http://www.s48.org/.
Type ,? (comma question-mark) for help.
> ,load s.scm                  <----- load the file
> (square 3/2)                 <----- invoke the function
9/4                            <----- the result from interpreter
> ^D                           <----- exit the interpreter
Exit Scheme 48 (y/n)? y
$