Introduction to UNIX

1. 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 2.0.30 on an i586 login: rdefe Password: $

12. Unix Login Red Hat Linux release 4.2 (Biltmore) Kernel 2.0.30 on an i586 login: rdefe Password: Login incorrect login: rdefe Password: $ • Login incorrect • Incorrect Login name? • Incorrect Password?

13. Unix Login • `$` = Command Prompt = Unix Shell • Bourne Shell • C Shell • Korn Shell • Bash Shell Red Hat Linux release 4.2 (Biltmore) Kernel 2.0.30 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: 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 $

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 $

18. Unix Commands $ date Mon May 25 12:44:04 EDT 1998 $ • 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

19. Unix Commands • cal • Displays Current Month $ cal January 1996 S M Tu W Th F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 $

20. Unix Commands • cal [month] [year] • Use Arguments to Display a specific Month & Year $ cal 10 1996 October 1996 S M Tu W Th F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 $ Arguments

21. Unix Commands • cal [year] • Display An Entire Year • Use Cntrl-S/Cntrl-Q to Pause/Unpause Screen $ cal 1996 1996 Jan Feb Mar S M Tu W Th F S S M Tu W Th F S S M Tu W Th F S 1 2 3 4 5 6 1 2 3 1 2 7 8 9 10 11 12 13 4 5 6 7 8 9 10 3 4 5 6 7 8 9 14 15 16 17 18 19 20 11 12 13 14 15 16 17 10 11 12 13 14 15 16 21 22 23 24 25 26 27 18 19 20 21 22 23 24 17 18 19 20 21 22 23 28 29 30 31 25 26 27 28 29 24 25 26 27 28 29 30 31 …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 $

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

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

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 tonym@dana.ccri.cc.r Sat Aug 23 22:54 12/402 job info U 2 kayj@dana.ccri.cc.r Tue Apr 12 19:51 60/1000 Re:passwd 3 cteng@dana.ccri.cc.r Sat Mar 12 14:59 15/348 mail 4 dryac@dana.ccri.cc.r Wed Feb 16 16:41 9/261 trouble & Mail Prompt - Enter Mail Commands

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

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 email

28. Unix Commands • mail commands • x - Exit without saving changes • No messages deleted • q - Exit save changes • Deleted messages are deleted • Read email 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 tonym@dana.ccri.cc.r Sat Aug 23 22:54 12/402 job info U 2 kayj@dana.ccri.cc.r Tue Apr 12 19:51 60/1000 Re: asswd 3 cteng@dana.ccri.cc.r Sat Mar 12 14:59 15/348 mail 4 dryac@dana.ccri.cc.r Wed Feb 16 16:41 9/261 trouble &

29. Unix Commands • Using mail to read saved mail files -f followed by the file name $ mail -f letters Mail version 5.5-kw 5/30/95. Type ? for help. "letters": 1 message 1 unread > 1 tonym@dana.ccri.cc.r Sat Aug 23 22:54 12/402 job 2 kayj@dana.ccri.cc.r Tue Apr 12 19:51 60/1000 lunch & $ 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 $ Press Cntrl-D to return to a $ prompt $ Message from rdefe@dana.ccri.cc.ri.us on ttyp0 at 22:59 ... This is a test of the write command <EOT> jsmith’s terminal

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

32. Unix Commands • man [unix command] • On-line Reference Manual • Spacebar - Display Next Page b - Previous Page • q - Quit • http://www.ntua.gr/cgi-bin/man-cgi $ 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 :