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Readings:

• read through rest of textbook (Chapters 4 and beyond)
• explore unix online resources

Topic: Intro to Unix I

Introduction to the unix operating systems

Why unix?

• 90% of the Internet is built on unix
• marketability - it is popular (knowledge will help you)
• additional vehicle for internet access

Student unix Accounts

• will be on ptph unix systems

h20.ptph.psu.edu -- h29.ptph.psu.edu

• email is disabled on these systems you can send but not receive

• launch telnet client
• set it to connect to one of the ptph systems
• when connected logon using userid and password

be sure to issue set term=vt100

History of Unix -I

 
       - Dennis Ritchie & Ken Thompson
 
        -- Bell Labs   1969
 
      - operating system for PDP-11/07
           - multiuser
           - multitasking
           - based on C programming language
           - many small utilities
           - ways to link programs
 
      - adapted to DEC VAX and given 'virtual memory'
 
           - Berkeley, 1979
                 - BSD unix 4.2
                 - BSD 4.3 given built-in tcp/ip networking
 
           - Mach -- developed at CMU
                 - used on NeXT
 
      - unix runs on many different types of computers
           - often hidden under a 'shell'
 
           - X-Windows, Motif, etc.
           - also note that the command-line interface in unix is
             called a shell and there are different ones

              - c shell, borne shell, korn shell, etc.

Overview

• case sensitive

unix - yes, DOS - no

• everything is a file
• hierarchical file structure

unix uses / as subdirectory separator

DOS uses \

• file specifications

unix - may be quite long but without spaces

complete file specification may include directory path

• delete line, delete character, halt process

for unix --> ctrl-u, ctrl-h, ctrl-c
 

• command structures and switches

unix --> command -switch parameters
 

Show online resources for unix from class web page

Intro to Unix - II

Basic Commands

• Good references (besides textbook) are the documents
• Unix is a 4-letter word and vi is a 2-letter abbreviation
• Unix help for beginners
• login and logout

 
• passwd - change password

 

show control characters (^u ^c ^h ^s ^q)

• ls - directory of files

use -l switch for detailed list
use -a switch for hidden files also
 

filename wildcards wildcards ? * and [ ]

(only ? and * used in DOS)

• mkdir, cd, rmdir, pwd -- directory create and navigate

 

• cp - copy (unix)

 
• mv, rm - rename, remove (unix)

 
• cat, head, tail - view parts of a file

 

pipe to more filter for easier viewing (DOS and unix)

• man - online unix manual

 
• Most Unix systems use the Unix File System (UFS)

chmod - file mode (protection) bits

(not applicable to DOS, although DOS files have 'attributes')

user - u group - g others - o

read - r write - w execute - x

example: chmod o+w fred.txt

dir example: chmod o+w .

• pipes & filters (unix and DOS)

use more to demonstrate ( help | more )

• I/O redirection (unix and DOS)
• jobs
• background jobs

(n/a with DOS)

sleep 10; who&

• ps command (ps ax)
• kill command