Some basic Unix commands

1
Some basic Unix commands

• Understand the concept of loggin into and out of
  a Unix shell
• Interact with the system in a basic way through
  keyboard and terminal window
• Create, copy and delete files, edit files
• Understand and use commands like ls cd mv cp rm
  cat date mkdir rmdir
• Be able to navigate up and down in the file system

2
Logging in and out

• As a Unix user you can log in and out
• When loggin in, the system checks your user name
  and password if correct, the system starts a
  shell for you and places you in the starting
  directory
• The shell runs as your process until you log out
• The shell gives you a prompt and interprets what
  you type

3
Interacting with the system

• Default input from the keyboard
• Default output to the terminal window
• When hitting return the shell interprets what you
  have typed
• The shell finds a command with that name and
  starts a process to execute the command
• During this time the shell process sleeps and
  wakes up when the command process is done

4
Working with files

• Creating files
• Can use vi or any editor
• Can use cat with input and output redirection
• Copying files
• cp makes a copy of an existing file
• cat can do it also, we practice this to
  understand I/O redirection
• Deleting files rm
• Editing files
• we will learn about vi, the most available Unix
  editor
• other editors are available on the system as
  applications

5
More important commands

• ls lists the files in the current directory by
  name
• cd changes your position in the directory tree
• mv moves a file from one directory to another
• rm deletes a file
• date prints the current date and time
• mkdir creates a directory
• rmdir deletes a directory (must be empty)?
• All Unix commands have options

6
Navigating in the directory tree

• The cd command changes your position in the
  directory tree, destination is parameter, it must
  be the name of a directory visible in the current
  directory
• cd without parameter
• Relative movement (relative pathname)?
• Absolute movement (absolute pathname)?
• cd .. and cd .

7
To Make a Good Password

• A good password
• Easily remembered by YOU
• Difficult to be guessed by others
• Tricks to make a good password
• Pick letters from a sentence
• I love Unix ? Ioenx
• Pick letters, numbers, and symbols that sound,
  look like, or replace a phrase
• I hate carrots! ? ih8s!
• A bad password not only harms you
• Attacks are much easier with a compromised
  account on a computer

8
Some Basic Commands

• who Who are using the system.

terra who katchab ttyp0 Aug 11
0847 scott tty02 Aug 10 1101 jenny tty03 Aug
10 0721

• who am i Who am I.

terra who am i katchab ttyp0 Aug 11 0847
9
Some Basic Commands

• ls List the files under current directory

terra ls readme cs211.2.ppt
cs211.ppt.gz notes.zip cs211.1.ppt
cs211.3.ppt make/ shell/

• cat Display the content of a file

terra cat readme Unix is easy! terra
10
Some Basic Commands

• Ctrl-c (press ltControlgt and c at the same time)
  Interrupt the current task.

terra cat c terra

• netscape surf the net. ONLY WHEN X is running

terra netscape

• lynx surf the net.

terra lynx www.yahoo.com
11
Some Basic Commands

• man See the manual page of a command.

terra man cat Reformatting page. Wait...
Done User Commands
cat(1) NAME cat - concatenate
and display files SYNOPSIS cat -nbsuvet
file ... DESCRIPTION cat reads each file
in sequence and writes it on the stan- dard
output. Thus example cat file
prints file on your terminal, and example
cat file1 file2 gtfile3 concatenates file1
and file2, and writes the results in
file3. If no input file is given, cat reads
from the stan- dard input file. OPTIONS--More
--(11)
12
Commands covered today

• File Manipulation Commands
• copy (cp), rename (mv), print (lpr), examine a
  file (head, more, cat), search a file (grep),
  delete (rm)
• Miscellaneous commands
• echo, date, cat
• Basic File Compression gzip, gunzip
• Finding Utilities and help
• which, whereis, apropos, man, info
• Communicating online
• Chat (write/talk) and email (pine)

13
Communication Utilities in UNIX
14
The talk Command
15
A Complete talk Session
16
A Complete talk Session
17
A Complete talk Session
18
The write Command
19
E-Mail Programs

• Some Programs available in Unix/Linux
• Mail most basic, low level mail command
• ELM
• PINE (PINE Is Not Elm), more user friendly text
  mail
• Outlook, GUI driven
• Eudora
• Netscape Mailer

20
Email Address
21
PINE

• A menu-driven client
• Uses pico as an editor
• Allows MIME attachments
• Main Menu
• C - Compose to write a message
• I or L - View messages
• Q - Quit

22
Local login
23
Remote Login