UNIX File Status: Read, Write, Execute
UNIX Commands

A listing of ls -l command is shown below:

drwx------   2 preddy        512 Jul 17  1995 Mail
-rwxr-xr-x   1 preddy       1670 Jun 11 16:38 demo.html
-rwx------   1 preddy         60 Mar  8  1995 usercount
-rw-------   1 preddy      16214 Jul 10 12:07 examples.tar.gz
drwxr-xr-x   8 preddy       8192 Jul 10 12:33 public_html

In the above data the first column represents the file status.

• If the first character is a "d" then this is a directory
• If on the other hand the first character is a "-" then this represents a file not a directory
• Let's analyze the second line of data -rwxr-xr-x demo.html
• the very first character - means this a file not a directory
• The remaining 9 characters are divided into three groups:
• rwx means the owner has read (r), Write (w), and Execute (x) privileges
• the next three characters stand for the group members of your project. These 3 characters in this example are: r-x which means they could read (r), but no write (-) privileges, and they can execute (x) the file.
• The last three characters represent others (neither the owner nor the group members).
• If you look at the third line usercount
• Only the owner has the read, write, execution privileges. Group members and other do not have any of these privileges, thus all three characters for these two entities are coded as --- (three dashes).

UNIX Commands

You type these command at the UNIX prompt-- either rvcc or $ sign.

ls		listing of files in your working directory
		Example: rvcc>ls

ls -l		listing of files in your working directory
		shows file status as well

ls -a		Shows all file names including the hidden (. files)
		such as .signature 

cd		Change directory to x

mv x y		Move file x into file y, i.e rename file x as y

cp x y		Copy file x into file y, now you will have two files

cp test.html public_html	Copy file test.html to a directory named
				public_html (if it exists)
				
finger		Gives a listing of currently logged in users

w		Listing of all currently logged in users and what they are
		executing

ls |m		Listing of files page by page

ls |pg		Listing of files page by page

grep "Reddy" /etc/passwd	Find a match for the string "Reddy" in the
				passwd file of the UNIX system

mkdir test	Makes a directory named test

rm test.html	Removes the file from your directory

rmdir test	Removes the directory test (make sure it is empty)

passwd		Allows you to change your password

telnet rvcc2	Telnets to rvcc2 assuming you were not on rvcc2

lpstat -a 	Shows a listing of all printer addresses

lp -s126_lzr index.html		Prints index.html on the laser printer in
				room # S126 (the first character is l as		
				in Larry, it is elzr after the underscore)

last thall	Shows the login activity of the user "thall" in the last x
		number of days

lo		Logs you out of the UNIX machine

or

exit		Logs you out of the UNIX machine

finger preddy	Shows when was the last time preddy logged on

finger @pilot.njin.net	May show all the currently logged on users at
			pilot.njin.net host machine

ping rvcc.raritanval.edu	Displays the status of the host machine 
				alive or down

nslookup rvcc.raritanval.edu	Shows the IP address of the host machine

archie internet		Starts archie search engine and locates all
			the ftp servers that have information about 
			the topic "internet"

gopher			Starts the menu-based gopher program 

script			Starts script and creates a file named "typescript"
			if you now do a telnet or irc, or gopher etc., the
			screen contents will be captured into file typescript.

ftp rvcc2.raritanval.edu	Initializes connection to an ftp server at
				rvcc2.raritanval.edu host address

pico test.html		Starts the editor pico and creates a file named
			test.html

irc			starts Internet Relay Chat program

whois Reddy		Gives a listing of all e-mail addresses of
			"Reddys" that are registered with Internic