LA-483 Lecture Outline

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 ntucsx unix systems

Logging onto unix account:

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

be sure to issue set term=vt100

To logout use logout

History of Unix

???- 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
everything is a file
hierarchical file structure

unix uses / as subdirectory separator

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

Basic Commands

Good references (besides textbook) are the documents

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 [ ]

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

cp - copy a file

mv, rm - rename, remove

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

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