Introduction to the UNIX operating system
	  (by Cynthia Brown, slightly updated since then.)

This is just a little help to get you started on UNIX. You do not
need to know much about UNIX to do your work for the course. If you
want to know more, there are lots of good UNIX books available at
most bookstores.

1. Unix distinguishes between capital and small letters. The files
   MYFILE and myfile and Myfile are all different files. Most people
   use lowercase letters for almost everything. This way you don't
   have to remember which one you used.

2. The "more" command will show you one screenful at a time. If you
   type "more myfile" the first screenful of myfile will be shown. 
   To go to the next screen, type a space.

3. The "cat" command will show a file on the screen. "Cat file1 file2"
   shows first file1 and then file2. "Cat file1 file2 >file3" puts
   a text consisting of file1 followed by file2 into file3. In general,
   >filename says to send the output of a process to file filename instead
   of the screen; <filename says to take input from file filename
   instead of the screen.

4. If I say "cat file1 file2 | more", the cat command will send its
   output to the more command, and I will see the results one screenful
   at a time. The character | is called a pipe, and can be used in 
   general to send the output from one process to be the input to another.

5. Here is a brief list of more useful commands. To get a fuller 
   explanation of any command, type "man command". This will show
   the manual page for the command on the screen.

   rm file     deletes a file
   cp file1 file2   copy file1 to file2
   mv file1 file2   move file1 to file2
   ls          list all the files in your directory
   vi file     edit
   grep string shows what files in my directory have lines with string in
               them.
   print -Pescher file     print to UNIX lab (room 201) printer (CCS only)
   a2ps file   print to UNIX lab (room 201) printer
   !l          repeat the last command that started with letter l
   history     show the last 20 commands (as your account is set up now)
   !5          repeat command 5 from the history list
   control c   kill the current process (Press <control> and <c> at same time.)
   control z   suspend the current process (Press <control> and <z> at once.)
   jobs        show suspended processes
   fg          resume suspended process (gets an argument if there is
                  more than 1)
   bg          resume a suspended process in background mode so you can
               do something else. It will still print to the screen if
               that is what it was doing.
   ps -alf     show all your current processes and their status
   yppasswd    change your password
   mail        send or answer mail (control d on a new line to send)
   finger name prints information about user "name"
   w           show the jobs on the system
   chmod       change file protection
   apropos word print info about commands relevant to word
   pwd         print working directory (in case you have lots of them)
   mkdir       make a new directory
   cd dir      change to directory dir
   cd ..       change to parent directory

6. File names: files are arranged in a tree of directories. The full name
   of the directory you start with is /home/yourname, where yourname is
   your login name. The full name of file myfile in this directory is
   /home/yourname/myfile. When you are in a directory you can omit the
   directory name prefix and just use the filename. The symbol ~ is an
   abbrevation for your directory name. If I am in directory 
   /home/brown/good and wish to copy file abc.txt from directory 
   /home/brown/work, I write
                cp ~/work/abc.txt abc.txt
   File names can have a wild card in them: an asterisk. rm *.l will ERASE
   all files in the current directory that have names ending in .l.
   rm *.* will erase all my files with a dot in their names! The student
   .login file has a command in it that changes rm so that it asks for
   confirmation before erasing a file. Once a file is gone, you will have
   to learn about ~/.snapshot (automatic backups) to get it back.
   So be careful!