Introduction to UNIX

2 History of Unix  1960 Software based on Hardware Limits  1969 Ken Thompson Develop a Better Programming Environment  1971 New Operating System - Unix Dennis Richie

3 History of Unix  Digital’s Role in Expanding Unix Introduced new PDP Computers 80% of all Colleges used DEC PDPs Included Unix  Unix Continues to Evolve Colleges & Universities AT&T Bell Labs

4 History of Unix  Problem Need to Port Unix to Other Platforms Unix written in Assembly Language  Solution Rewrite Unix Using `B` `B` Limitations `B` Required Modifications to Write Unix

5 History of Unix  `B` Programming Language Extensive Changes Made For Unix  Renamed to `C` High & Low Level Programming Language Increased Portability Easier to Improve & Enhance Unix

6 History of Unix  1983 AT&T Announces Unix System V 1st Commercial version of Unix Unix Improvements Continue…  Unix System V Interface Definition (USVID) Clearly Defines Unix Interface Opens Unix Development

7 Using Unix  Graphical Interface Xwindows  Command Line Command Prompt

8 Unix Philosophy  Simple and Easy to Use  Make Each Program Do One Thing Well  Expect the Output of One Program To Be The Input Into Another  Build New Programs to do the Job  Small is Beautiful

9 Accessing Unix  Connect to Unix  Login  Password  Perform Necessary Work  Logout

10 Important Usage Notes  Return Key  ESC (Escape Key)  Ctrl (Control Key)  Unix Is Case Sensitive Upper Case and Lower Case Are Different! Use Lower Case

11 Unix Login  `$` Unix Command Prompt  Ready For Next Command Red Hat Linux release 4.2 (Biltmore) Kernel on an i586 login: rdefe Password: $ Red Hat Linux release 4.2 (Biltmore) Kernel on an i586 login: rdefe Password: $

12 Unix Login  Login incorrect Incorrect Login name? Incorrect Password? Red Hat Linux release 4.2 (Biltmore) Kernel on an i586 login: rdefe Password: Login incorrect login: rdefe Password: $ Red Hat Linux release 4.2 (Biltmore) Kernel on an i586 login: rdefe Password: Login incorrect login: rdefe Password: $

13 Unix Login  `$` = Command Prompt = Unix Shell Bourne Shell C Shell Korn Shell Bash Shell Red Hat Linux release 4.2 (Biltmore) Kernel on an i586 login: rdefe Password: $ Red Hat Linux release 4.2 (Biltmore) Kernel on an i586 login: rdefe Password: $

14 Changing Your Password  Select a ‘Good` Password 7 Characters, Include Non-Alphas $ passwd Password: New password: New password (again): Password changed passwd: all authentication tokens updated successfully $ exit Login: $ passwd Password: New password: New password (again): Password changed passwd: all authentication tokens updated successfully $ exit Login: Cntrl-D can also be used to logout

15 Changing Your Password  When The Command Doesn’t Work Too Short or Too Simple $ passwd Password: New password: it's WAY too short New password: Password change aborted passwd: Authentication token manipulation error $ $ passwd Password: New password: it's WAY too short New password: Password change aborted passwd: Authentication token manipulation error $

16 Correcting Typing Errors  Backspace Key Cntrl-h is also backspace  Cntrl-c Ignore current line, return to $ Stop Currently Running Command

17 Unix Commands  Making a Mistake The Command Interpreter `bash` Responds `Command not found` $ x bash: x: command not found $ $ x bash: x: command not found $

18 Unix Commands  date Current System Date & Time Note: No Arguments & No Options  Argument Extra Information Passed along to the command  Option Causes the command to do something different $ date Mon May 25 12:44:04 EDT 1998 $ $ date Mon May 25 12:44:04 EDT 1998 $

19 Unix Commands  cal Displays Current Month $ cal January 1996 S M Tu W Th F S $ $ cal January 1996 S M Tu W Th F S $

20 Unix Commands  cal [month] [year] Use Arguments to Display a specific Month & Year $ cal October 1996 S M Tu W Th F S $ $ cal October 1996 S M Tu W Th F S $ Arguments

21 Unix Commands  cal [year] Display An Entire Year Use Cntrl-S/Cntrl-Q to Pause/Unpause Screen $ cal Jan Feb Mar S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S …more... $ cal Jan Feb Mar S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S …more...

22 Unix Commands  who Display Current Users Note: No Options & No Arguments $ who rdefe pts/2 Aug 23 20:25 jsmith pts/5 Aug 23 22:30 rdefe pts/1 Aug 23 13:53 $ $ who rdefe pts/2 Aug 23 20:25 jsmith pts/5 Aug 23 22:30 rdefe pts/1 Aug 23 13:53 $

23 Unix Commands  who -q option  Display a Quick List of Current Users $ who -q rdefe jsmit sbrow users=3 $ $ who -q rdefe jsmit sbrow users=3 $ Option

24 Unix Commands  mail [login id] Sending Unix Mail $ mail johnd Subject: Test Hello there This is a test of my first unix $ $ mail johnd Subject: Test Hello there This is a test of my first unix $ Add additional logins here To send, hit Cntrl-D on a Blank Line Can only correct the line your currently on

25 Unix Commands  mail Reading Unix Mail $ mail Mail version 5.5-kw 5/30/95. Type ? for help. "/var/spool/mail/rdefe": 1 message 1 unread >N 1 Sat Aug 23 22:54 12/402 job info U 2 Tue Apr 12 19:51 60/1000 Re:passwd 3 Sat Mar 12 14:59 15/348 mail 4 Wed Feb 16 16:41 9/261 trouble & $ mail Mail version 5.5-kw 5/30/95. Type ? for help. "/var/spool/mail/rdefe": 1 message 1 unread >N 1 Sat Aug 23 22:54 12/402 job info U 2 Tue Apr 12 19:51 60/1000 Re:passwd 3 Sat Mar 12 14:59 15/348 mail 4 Wed Feb 16 16:41 9/261 trouble & Mail Prompt - Enter Mail Commands

26 Unix Commands  Reading Mail + (Enter Key) - Display Next Message - Display Previous Message 3 To Display Message 3 $ mail Mail version 5.5-kw 5/30/95. Type ? for help. "/var/spool/mail/rdefe": 1 message 1 unread >N 1 Sat Aug 23 22:54 12/402 job info U 2 Tue Apr 12 19:51 60/1000 Re:passwd 3 Sat Mar 12 14:59 15/348 mail 4 Wed Feb 16 16:41 9/261 trouble & $ mail Mail version 5.5-kw 5/30/95. Type ? for help. "/var/spool/mail/rdefe": 1 message 1 unread >N 1 Sat Aug 23 22:54 12/402 job info U 2 Tue Apr 12 19:51 60/1000 Re:passwd 3 Sat Mar 12 14:59 15/348 mail 4 Wed Feb 16 16:41 9/261 trouble &

27 Unix Commands  mail commands h - Display Mail Header Information s [message list] filename - Save message to a file d [message list] - Delete message u [message list] - Undelete message R - Reply to Author r - Reply to All mail [login] - Send

28 Unix Commands  mail commands x - Exit without saving changes  No messages deleted q - Exit save changes  Deleted messages are deleted  Read moved to a file named mbox $ mail Mail version 5.5-kw 5/30/95. Type ? for help. "/var/spool/mail/rdefe": 1 message 1 unread >N 1 Sat Aug 23 22:54 12/402 job info U 2 Tue Apr 12 19:51 60/1000 Re: asswd 3 Sat Mar 12 14:59 15/348 mail 4 Wed Feb 16 16:41 9/261 trouble & $ mail Mail version 5.5-kw 5/30/95. Type ? for help. "/var/spool/mail/rdefe": 1 message 1 unread >N 1 Sat Aug 23 22:54 12/402 job info U 2 Tue Apr 12 19:51 60/1000 Re: asswd 3 Sat Mar 12 14:59 15/348 mail 4 Wed Feb 16 16:41 9/261 trouble &

29 Unix Commands  Using mail to read saved mail files $ mail -f letters Mail version 5.5-kw 5/30/95. Type ? for help. "letters": 1 message 1 unread > 1 Sat Aug 23 22:54 12/402 job 2 Tue Apr 12 19:51 60/1000 lunch & $ mail -f letters Mail version 5.5-kw 5/30/95. Type ? for help. "letters": 1 message 1 unread > 1 Sat Aug 23 22:54 12/402 job 2 Tue Apr 12 19:51 60/1000 lunch & -f followed by the file name $ mail -f Reads the file mbox when the file argument is left out

30 Unix Commands  write [login] Send a message to the screen someone’s screen $ write jsmith This is a test of the write command $ $ write jsmith This is a test of the write command $ Press Cntrl-D to return to a $ prompt $ Message from on ttyp0 at 22:59... This is a test of the write command $ Message from on ttyp0 at 22:59... This is a test of the write command jsmith’s terminal

31 Unix Commands  mesg Turn online messages on/off $ mesg is y $ mesg n $ mesg is n $ mesg is y $ mesg n $ mesg is n Display current message status Turn messages off

32 Unix Commands  man [unix command] On-line Reference Manual Spacebar - Display Next Pageb - Previous Page q - Quit $ man who WHO(1) NAME who - show who is logged on SYNOPSIS who [-imqsuwHT] [--count] [--idle] [--heading] [--help] [--message] [--mesg] [--version] [--writable] [file] [ami] DESCRIPTION This documentation is no longer being maintained and may be inaccurate or incomplete. The Texinfo documentation is : $ man who WHO(1) NAME who - show who is logged on SYNOPSIS who [-imqsuwHT] [--count] [--idle] [--heading] [--help] [--message] [--mesg] [--version] [--writable] [file] [ami] DESCRIPTION This documentation is no longer being maintained and may be inaccurate or incomplete. The Texinfo documentation is :