CD(change directory)
Description:changes current directory to a new directory. Also takes you to your MAIN directory.

cd .. will change the directory one back from the current directory.

For Example
lunar/u2/username/public_html/images would go back to lunar/u2/username/public_html

Syntax: [ cd directory ] takes you to desired directory
[ cd ] takes you directly to your MAIN directory.

Chmod(change mode)

Numeral Meaning
400 Owner has read permission
200 Owner has write permission
100 Owner has execute permission
040 Group has read permission
020 Group has write permission
010 Group has execute permission
004 All users have read permission
002 All users have write permission
001 All users have execute permission


There are 2 methods for using chmod. The first is numerical the second is alphabetical.
The proper usage is [ chmod number filename ]


1. The numerical method can be used to change permissions individually:
[ chmod 400 index.html ]
This gives the owner ,which would be you, permission to read this file.
2. You can also add one or more of the permissions together to get a combined effect:
[ chmod 440 index.html ]
now this will give permission for you and the group to read your index.html file.

The most important thing to remember when using the chmod number scheme is use chmod 644 (filename) for files and chmod 755 (directory name) for directories. This will set the permissions so the webpage can be seen.

Character Meaning
u User (think of it as U-You)
g Group
o Other (or the world)
a All (all three previous goups)
+ (plus sign) Adds permission
- (minus sign) Takes away permission
r Reads the file
w Writes to the files
x Executes the file

The command syntax is similar to the numeric method.
[chmod a+r index.html]
This will allow all three groups to read this index.html file
ALL HOMEPAGES MUST be able to be read by all three


Description: copies the contents of one file into another

Syntax: cp [ options ] filename newfilename

Options Meaning
-i Makes sure you don't overwrite an existing file
-p Retains existing permissions
-r Copies entire directory


Description: file text editor used to make changes to homepages

Syntax:[ emacs filename ]


Description: substitute logout command

Syntax:[ exit ]

FTP(file transfer protocol)

Description: used to connect to other networks and transfer files to and from your computer

UNIX Syntax:[ftp remote machine] for example [ ftp ]

from the <ftp> prompt you can then enter the following commands to transfer files.

Command Result
get filname gets file from remote computer
get filename1 filename2 gets file from remote computer and saves it to your computer as filename 2
close close out of remote computer but keeps <ftp> session running
quit terminates ftp session
pwd lists the current directory on the remote machine


Description: printer command used in dimacs netscape and at X session prompt to print desired files

Syntax: [ lpr -P(<--capital P) printername ] The printer at dimacs is statler


Description: lists the files in your account directories

Syntax: ls [ or ls -option ]

Options Meaning
-l lists directory content in long form
-al lists all contents in directory including hidden files
-d lists only the directories , not the contents

MKDIR(make directory)
Description: creates a new directory

Syntax: [ mkdir directoryname ]


Description: moves a file or multiple files into another directory, and also moves a file to a new name in the directory (like a change name command)

Syntax:[ mv filename directory OR mv filename newfilename ]


Description: displays the directory and or sub directories in which you are currently located

Syntax: [ pwd ]


Description: deletes files

Syntax: [ rm filename ]


Description: logs in to a remote system

Syntax:[ telnet hostname ]

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