Basic UNIX Commands
To succeed in Math 211, there are relatively few UNIX
commands that you will need to know. Here is a short list, together
with how to use them. In what follows, expressions like ls
indicate commands that have to be entered at the UNIX prompt. The
expression filename will stand for a filename of your choice.
E.g., rm filename should be entered if you want to
delete the file from the computer. If the name of the file is really
garbage, then what you want to enter is rm garbage.
-
ls
- is used to list all of the files in the current directory. For
example, if there is a file is in the computer, but you aren't sure of
what the file name is, simply enter ls. You will be presented with
a list of all files in the current directory. If the file name you
want is not on the list that the computer presents you with, then it
is not there.
-
rm filename
- will cause the computer
to delete the file from its memory.
This deletion is permanent! For that reason the computer will ask you
if you are sure by responding rm:remove filename? If you respond with
anything but yes (just y will do), the
file will not be removed.
-
cp
- is the copy command. The entry
cp filename1 filename2 will result in
a new file with name filename2,
which will have exactly the same contents
as filename1. If there already was a file with name
filename2, the computer
will respond overwrite filename2?
If you respond with anything but a
yes (or y), the cp command will be ignored.
-
mv
- is the move, or rename command.
The entry mv filename1 filename2
will result in filename1 being renamed filename2.
If there already was a
file named filename2, the computer will respond
remove filename2? If you
say yes, the contents of the old filename2 will be lost.
-
cat
- is short for concatenate.
This command has a variety of uses,
but the most common one is to print the contents of a file to the
screen. Simply enter cat filename,
and the contents of the file will
appear on the screen.
-
more
- is the substitute for cat
when the file is too long to fit on
one screen. The command more filename
will cause the file to appear on
the screen one screenful at a time. Simply hit the spacebar when you
want a new page to appear. Unfortunately you cannot page backwards.
After you have created a few files in your home directory, you will
want to organize them. The way to do this is to put the files in
appropriately named subdirectories. Here are the basic commands for
doing this.
- cd
- stands for change directory.
All by itself, cd will put you in the account's main
directory. Used in conjunction with the name of a subdirectory, as is
cd directory, it will result in changing location to
the named subdirectory.
- mkdir directory
- will create a new
subdirectory with the name provided.
- rmdir directory
- will delete the indicated
directory. There is one catch. The directory must be empty or the
command will not be executed.
You will occasionally want to print a file:
-
lpr
- is the command to use when
you want a hard copy of a file while using an Owlnet workstation. The
command lpr filename will cause the
file to be printed on a line
printer. The command lpr -Pps filename
causes the file to be printed
on a nearby laser printer. Ask a fellow student to
find out which printer will be used.
More complete information on
UNIX is available.
Last modified: Tue Aug 27 11:55:37 CDT 1996