web design radford university school of communication

Permissions and navigation in Unix in the  Radford system:                    

Login:

Using a Mac, use Terminal application / PC should be Telnet or other line command internet protocol ap

(Using a PC on campus -__________, or download applications like putty )

ssh -l  loginname ruacad.radford.edu  

Following the password prompt, you will see

Type xterm-color unknown
tcsh: using dumb terminal settings.
TERM = (ruterm)  

At this prompt, type VT100
So that the line reads  TERM=(ruterm) VT100

Navigating

pwd                         print working directory (where am I?) 

man                         help manual to get information, ex.: man ls 

who                        who else is logged on

ls                              list structures  (show files)

ls -C                        list structures  in columns

ls  -R                       list structures  everything

ls -l                        list structures with permissions and other info

ls –a                      list structures and show invisible files too

ls -l |more              list structures with permissions and "pipe" to more

cd ..                                     go up a directory (that's cd space dot dot)

cd foldername              go into a directory

mkdir foldername                          make a new directory

rmdir  foldername                          remove a directory 

rm  name                        remove a file

mv name newname            rename a file

Three ways to open and (two ways to) edit a file: 

pico filename -- open existing file / make new one using "pico" editor

vi filename -- open existing file / make new one using "vi" editor 

more filename -- open existing file in  "read only" mode / use space bar to continue, hit q to get out. 

Pico editor commands

<control> X   quit                                     <control>K            cut

<control> U  undo                                    <control>G   Help

vi editor  commands

<esc>  toggle (switch back and forth)  command and write modes                        

u           undo

i             insert mode                                                r            replace on character

R            replace mode (overwrite)                         x             delete a character

dd             delete a line                                         10 dd delete 10 lines

l             move left one character                         e            move left one word 

k            move up one line                                     j            move down one line

h             move right one character                        man            Help  (manual)

<esc> :q!             quit without saving changes

<esc> :wq            quit and save changes (write quit)

<esc> :w!      save changes (write)

Changing permissions  

1. The basic command is chmod  followed by a space, then what type of permission you want followed by another space, then the folder name, the file name or the special command for all files.

EX:              chmod   755   file1.html               -- Standard web for a file called "file1.html" 

                   chmod   755   *.*                        -- Standard web permission for all files in the folder

                    chmod   755   foldername            -- Standard web permission for a  folder (directory)

EX2:  If you are setting permissions for a dynamic_php folder or files, the permissions look like this: 

            Chmod   711   file1.html            -- and so on. 

2. What does it mean?  

If you type ls –l to find the permissions, you might get something that looks like this: 

            drwx------   22 bill  staff     748 Jan 20 23:41 Sites

This is a directory with owner read write execute permission but no permission for group or other.   Here is one with permission for group and other:

            drwxr-xr-x   22 bill  staff     748 Jan 20 23:41 Sites 

See the difference?  The last six places in the permission line now have r-x  which means read not write and execute.  Read write execute would be rwx  and read only would be r—