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 Lesson - 1


 REVIEW OF BASIC UNIX CONCEPTS 

P0

Advanced UNIX User|Forward|1-0.1|13,54
     Dear UNIX User, congratulations on your 
progress in learning the UNIX System!


     At this point you should have finished CTI's 
Getting Started In UNIX and The UNIX User tutorials,
and/or understand the concepts presented in those 
tutorials.


     If you find the material in this lesson new to 
you, please review The UNIX User tutorial before 
proceeding.

MENU

Basic Concepts: Review|Topics to Learn|1-0.2|12,46
   #            Topic
  ---           -----
   1  -  Review of Basic Concepts
   2  -  UNIX Software Resources
   3  -  UNIX Hardware Resources
   4  -  The UNIX Editors
   5  -  The UNIX File System
   6  -  Input/Output Redirection
   7  -  UNIX Pipes and Background Processing
   8  -  Lesson Review
   0  -  Return to the Main Menu

P1

Basic Concepts: Review|Software Resources|1-1.1|12,57
     UNIX is a multi-user operating system because on
most UNIX systems several users may be logged in at 
the same time.


     UNIX is a multi-tasking operating system because 
a user can run more than one program at a time.


     Some UNIX systems have more than one processor 
executing program(s) simultaneously (in "parallel"), 
thus UNIX has the capability of handling parallel
processing.

P2

Basic Concepts: Review|Software Resources|1-2.1| 1 , 25
 UNIX SOFTWARE RESOURCES 

P3

Basic Concepts: Review|Hardware Resources|1-3.1|14,55
     As you recall, the integral components of your 
computer system are the central processing unit (CPU), 
the primary memory, the system disk (secondary memory), 
the system console and the keyboard.


     Besides the integral components, your UNIX system 
is probably equipped with several other peripheral
devices including:

       * an off-line printer,
       * one or two floppy disk drives,
       * a magnetic and/or cartridge tape drive, or
       * an optical disk, etc.

P4

Basic Concepts: Review|Hardware Resources|1-3.2|17,54
     By now you should know how to:

   *  move around in the directory hierarchy,
   *  use basic file manipulation commands,
   *  use the vi editor to create and modify files,
   *  send files to your off-line printer,
   *  perform inter-user communications,
   *  use input-output redirection facilities,
   *  use pipes,
   *  format magnetic media, and
   *  use the commands for reading and writing to the 
      magnetic media, 


     In case you are unfamiliar with these tasks, 
please review CTI's Getting Started in UNIX and 
The UNIX User tutorials before proceeding with this
course.

P5

Basic Concepts: Review|UNIX Editors|1-4.1|11,56
     The UNIX editors provide the capability for:

       *  creating files,
       *  making changes on the current line,
       *  making changes affecting multiple lines,
       *  context searching, and
       *  interrupting and performing external commands.


     The UNIX distribution includes a line editor, ed
and, on most versions, the premier UNIX screen editor, vi.

P6

Basic Concepts: Review|UNIX Editors|1-4.2|16,48
     UNIX systems generally come with several 
different types of editors including:

         *  line editors:  ed, ex, edit
         *  screen editors:  vi
         *  stream editors:  sed


     Other editors and word processing packages are 
available from third party sources.  In particular,
emacs, which has windowing and other powerful
features.


     Another commercial UNIX word processor is
Lyrix available from the Santa Cruz Operation.

P7

Basic Concepts: Review|The UNIX File System|1-5.1|6,54
     The file system is a uniform set of directories 
and files arranged in a tree-like, hierarchical structure.


     Files are grouped into directories and directories 
are organized in a hierarchy.

P8

Basic Concepts: Review|The UNIX File System|1-5.2|10,54
     A pathname is the complete name of a directory or 
a file.


     A pathname traces the path through the file system 
to the desired file.


     The top of the hierarchy is a special directory 
called root, with the pathname /.

P9

Basic Concepts: Review|Input/Output Redirection|1-6.1|11,52
     Many utilities such as:

ps, ls, who, date, pwd, and echo

use the standard output (usually your terminal 
screen) to deliver the output to you.


     Interactive programs read information from the 
standard input (usually your terminal keyboard) and 
write their output to the standard output.

P10

Basic Concepts: Review|Input/Output Redirection|1-6.2|13,53
     By using the input redirection facility which is 
signified by  < , one may use the contents of a file
as the input to a program that normally expects input 
from the standard input.  For example:

 prog.run  <  data.in 


     The output from the program that usually writes 
to the standard output may be redirected to a file 
with  > :

 prog.run  >  data.out 

P11

Basic Concepts: Review|Pipes and Background Processing|1-7.1|13,58
     The pipe provides a user with the means of connecting 
the output of one command to the input of another, i.e., 
what comes out of one process is piped into another.


     The pipe process is signified by the shell character  | .
For example,

 ls -l  |  wc  -l 

will use the output of the ls command as input to the
wc command.  In other words, this command will count 
the number of files in the current directory.

P12

Basic Concepts: Review|Pipes and Background Processing|1-7.2| 14 , 51
     UNIX is a mult-processing system; therefore, 
it permits one to execute more than one program or 
process at a time.  The process(es) that the user 
chooses to run unattended are said to be running 
in the background, while the attended process is 
running in the foreground.
???BSD: add control z, fg, bg for Bsd--pull 1sa_jobs 1sa_bg 


     A command or process will run in the background 
if it is invoked by appending an  &  to the end of 
the command line, e.g.,

 doit  <  chapter_1  >  result &