password

When you received your username and password from the consulting desk, the password was a generated password. You should personalize your own password so that it is easy to remember without being something others could easily guess. It should not be a word that is in a dictionary (as a program can be written to try all the words in a dictionary in seconds). Your password has to be at least 6 characters. It can be letters (UPPER case or lower case) or numbers. CHANGE IT!

DO NOT give your password to others. This is an account and you are responsible for what is done on this account. If you give the password to someone else and they do something wrong, your account information will be pointing to you. DO NOT give your password to others.

If or when you change your password, it might take a few minutes for the new password to be activated. There are several changes that must take place on several computers. Be patient. If you just changed your password and the new password doesn't work yet, the old password is still active and it will work.

type this in	this is what it will do
sunburst% password	you will be prompted to enter your old password
old password	enter your old password here
new password	you will be asked to enter a new password
new password	type it again for verification

ls (list schema)

The ls command displays the files and directories in your current working directory. If there are no visible files in your directory, the UNIX prompt will be returned. ls does not display hidden files which begin with a . (period). To display all files you must include the option -a.

type this in	this is what it will do
sunburst% ls	displays the files and directories in your current directory
sunburst% ls -a	displays all files and directories (even the hidden ones)
sunburst% ls -l	displays all files and directories w/FULL description
sunburst% dir	same as ls -l (alias for DOS people)
sunburst% ls -R	displays all files and directories in current directory and below (recursive)

You should not delete or change any hidden files. These files are created for administrative use of your e-mail, news readers, login, etc.

mkdir (make directory)

The mkdir command will create a subdirectory inside of your current working directory. If you are logged into sunburst go ahead and try the command as follows.

type this in	this is what will happen
sunburst% mkdir tutor_stuff	this will create a subdirectory called tutor_stuff

Now let us look to make sure the directory was actually created.

sunburst% ls

should display your files and subdirectories in your current working directory (including the subdirectory you just created.)

cd (change directories)

The cd command will change the current working directory to the location or path you type.

sunburst% cd tutor_stuff	change the working directory to tutor_stuff
sunburst% cd ..	cd followed by .. will take you to the current parent directory
sunburst% cd	cd by itself will take you to your home directory no matter where you currently are
sunburst% cd tutor_stuff	change the working directory to tutor_stuff

If you type in the ls command here (make sure you are inside of tutor_stuff) you should see that the directory (you just created) is empty. Try it and see! Now that you are in the directory called tutor_stuff create another subdirectory called more_stuff. We will use this subdirectory later.

touch (touches a file and updates it)

The touch command will update the last time a file was edited. If you touch a file that doesn't yet exist, it will create a file with zero length. You probably won't use it much, but it will allow us to easily create files that we will use and delete later.

sunburst% cd ~/tutor_stuff	makes sure everyone is in the right place
sunburst% touch testfile	creates a file named testfile
sunburst% ls	check to see if the file is there

Create another file of your own choice. Make sure you remember the name so you can delete it later.

pwd (print working directory)

The pwd command shows you where you are (path wise) on the computer (server - not your desktop). You have probably noticed that every time you change directories you get a description of the path. Sometimes it is necessary to know your current path without changing to a different directory.

sunburst% cd	takes you to your home directory
sunburst% pwd	prints your working directory you should see something like /home/coyote/username
sunburst% cd tutor_stuff	takes you to tutor_stuff subdirectory
sunburst% pwd	you should see /home/coyote/username/tutor_stuff

See if you can get back to the more_stuff subdirectory. Next, have the full pathname printed to the screen using the pwd command. (Can you guess what the full pathname will be?)

Miscellaneous stuff about directories and pathnames

Follow the directions and make sure you understand what is happening.

sunburst% cd	takes you to your home directory
sunburst% ls	lists files and directories in the current directory
sunburst% ls tutor_stuff	lists files and directories inside of tutor_stuff
sunburst% ls what	is not a directory and will say "what not found"
sunburst% ls ~	lists files and directories in your home directory (no matter where you currently are in the system)

The tilde (~) is a reference to your home directory.

cp (copy file)

You can make an exact copy of a file using the copy (cp) command.

sunburst% cd ~/tutor_stuff	makes sure everyone is in the right place
sunburst% cp testfile file2	makes a copy of testfile and calls it file2
sunburst% dir	make sure the files are really there

See if you can make a copy of file2 (call it file3).

mv (move file)

The mv command moves files and directories around in the file system. You can also use the mv command to rename a file. To make sure these examples work you must be inside of tutor_stuff with the testfile and file2 created.

sunburst% mv testfile file1	renames testfile with the name of file1
sunburst% mv file1 ..	moves file1 to its parent directory
sunburst% mv file2 more_stuff	moves file2 into subdirectory more_stuff

See if you can move the file2 that is in more_stuff back to tutor_stuff. Also move the file1 that is in home directory back to tutor_stuff. If you do this you should have file1, file2, and file3 inside of tutor_stuff. Use the dir or ls commands to make sure you moved the files to the right spots.

rm (remove file)

The rm command removes or deletes files from the file system. You must be careful. DO NOT delete anything you might need later. You can't get it back.

sunburst% rm file1	removes file1
sunburst% rm file3 ..	removes file3

Check to see that file2 still exists and that file1 and file3 are gone. Then remove file2.

rmdir (remove directory)

The rmdir command will remove an empty directory. If you have followed closely up to this point you should not have any files in the subdirectory more_stuff, so let's remove that directory.

sunburst% cd ~/tutor_stuff	makes sure everyone is in the right place
sunburst% rmdir more_stuff	removes directory called more_stuff

See if you can remove the directory tutor_stuff. You need to make sure that there are no files or directories inside. (Remember you created another file of your choice - with a touch command earlier.)

chmod (changing a file mode)

The chmod command lets the owner of a file change the permissions settings for a file or directory. These permissions are displayed with the dir or ls -l listings. The permissions are in the form of

-rwxrwxrwx

This collection of letters tells us how the permissions for a file (starting with a -) or directory (starting with a d) are set. The first three letters give the permissions for the owner of the file. The middle group (next three letters) give us the permissions for the group to which the owner belongs. The last three letters tell the permissions for everyone else. The permissions can be set for directories as well as files but have slightly different meanings.

files

• r- read permission
• w-write permission
• x-execute permission

directories

• r-permission to list files in a directory
• w-permission to delete files or move files
• x-permission to access to files in the directory

permissions owner group everyone - rwx rwx rwx

codes r - Read Permission 4 w- Write Permission 2 x- Execute Permission 1

If you wanted to set a file with full permissions for yourself or owner (4+2+1)=7, read and write permissions for the group (4+2)=6 and read only for everyone 4=4, the command would be

chmod 764 filename.

Depending on what you are doing with (and from) the files, the permissions need to be set appropriately for owner, group and everyone.

du (disk utility)

The du command prints the number of kilobytes you have in each subdirectory. This can be useful to see which directory has the most files if you have gone over quota. From your home directory type
sunburst% du

quota (displays user quota and usage)

Each user on sunburst is allocated a certain amount of disk space (usually about 5 megabytes). If you exceed this quota some of your files must be removed within a certain time period. To check your quota and see how much you are using type
sunburst% quota -v

clear (clears screen)

The command clear just clears your terminal screen. Go ahead and try this. You should see a clear terminal window with sunburst% at the top.

Ways to display file contents

In order for us to experiment with the next five commands, we need to create an example file. To do this you can either type the list below exactly as it appears or you can highlight (or select) the list below and cut-n-paste it into UNIX at the sunburst% prompt. Either way will work the same. In this example we are sending the input from the keyboard into the file demofile. AFTER the list is either typed into UNIX or pasted from Netscape into UNIX you must stop the input with a return and a control-d.
---------------------------list below
cat > demofile
one
two
three
four
five
six
seven
eight
nine
ten
eleven
twelve
thirteen
fourteen
fifteen
sixteen
seventeen
eighteen
nineteen
twenty
twenty-one
twenty-two
twenty-three
twenty-four
twenty-five
twenty-six

------------------list above
AFTER the list is either typed into UNIX or pasted from Netscape into UNIX you must stop the input with a return and a control-d.

cat (concatenate)

The cat command will display the entire contents of the file on the terminal screen. If it is more than one page it will all scroll by quickly.

sunburst% cat demofile

displays entire file contents to terminal screen

more (display one screen at a time)

To display the entire file one screen at a time use the more command instead of cat. After each screen is drawn you must hit the space bar to go on to the next screen.

sunburst% more demofile

displays the file example one screen at a time

head (display first 10 lines of a file)

The head command will display the first 10 lines of a file.

sunburst% head demofile

should display one - ten in our demofile

tail (displays last 10 lines of a file)

displays last 10 lines of a file

sunburst% tail demofile

should display seventeen-twenty-six in our file

wc (word count)

The wc command will tell you how many lines, words and characters.

sunburst% wc demofile

would return 26 lines 26 words and about 170 letters If you pasted the info from Netscape there would be a few more letters because of additional spaces used in formatting HTML (approximately 383 letters).

* (wild card - matches none or more )

The * is a wild card that will replace anything in its place. Below are some examples of its use.

sunburst% dir *.gif	displays all files ending with .gif
sunburst% dir test*	displays all files beginning with test

? (wild card - matches just one character)

The ? is a wild card that will match one character only. Below is an examples of its use.

sunburst% dir test?.gif

displays all files starting with test then valid character then ending with .gif would not find test10.gif

file name conventions

Unix file names should contain only letters, numbers, underscore and period (. often referred to as dot). The file names can contain up to 256 characters. Try to give your file names meaning. Don't use all 256 characters.

Directories are basically a special type of file, so the rules for naming files apply to directories also.

!!

This is called the bang bang command. It will repeat the last command entered into unix from your keyboard. This is like the F3 command from DOS.

Try it!

A variation of this is ! followed by a letter (or letters). This will re-issue the last unix command that started with that letter (or letters). Lets look at the following example:

sunburst% dir	would display the current working directory
sunburst% !!	would repeat last command
sunburst% mkdir stuff	creates directory stuff
sunburst% clear	clears the terminal window
sunburst% cd stuff	change working directory to stuff
sunburst% !c	would try to change directories again this wouldn't work because you are already there
sunburst% !cl	would send the last unix command starting with cl which would be clear

More help directly from UNIX here

man

Read the UNIX on line manual page for a specific command.

sunburst% man cp

displays online manual for copy command

Notice the --More--(26%) message at the bottom of the screen (if you type the above command). If you do not want to view the remaining pages you can [interrupt Process] with the Control-C command.

whatis

The whatis command will display a one-line explanation of a command.

sunburst% whatis cp

displays a one-line description of the cp command

apropos

If you don't remember the UNIX command but you know you want to copy a file you can use the apropos command to find reference to the copy command within the online manual.

sunburst% apropos copy

displays references to copy within the online manuals

finger

If you want to find out some information about another user (such as: are they logged on, when did they read their mail last, do they have a plan) you can use the finger command. The finger command reads some of those invisible files in your directory we were talking about earlier to display the information you will see on your screen.

sunburst% finger username@host

displays information regarding the person you are checking on

talk

If you fingered someone and know that they are currently logged into sunburst you can talk to them. The talk command will split your window into a upper portion and lower portion. You will type on one and read the person's responses an the other port ion. It is kind of like a telephone (well no sound). You can do this with anyone in the world that is logged on if you know their e-mail address.

After you issue the talk command the other person should see a message that says you are requesting to talk to them. If they want to talk to you they need to type in a corresponding message on their computer screen.

sunburst% talk username@host

allows you to talk to someone else over internet