Transcript A Small UNIX Tutorial

A Mini UNIX Tutorial
What’s UNIX?
 An operating system run on many
servers/workstations
 Invented by AT&T Bell Labs in late 60’s
 There are many different versions of UNIX,
although they share common similarities. The most
popular varieties of UNIX are Sun Solaris,
GNU/Linux, and MacOS X.
 The UNIX operating system is made up of
three parts; the kernel, the shell and the
programs
 The shell acts as an interface between the
user and the kernel. When a user logs in, the
login program checks the username and
password.
To open an UNIX terminal window, click on the
"Terminal" icon from Applications/Accessories menus.
n UNIX Terminal window will then appear with a % prompt,
waiting for you to start entering commands.
Files and processes
 Everything in UNIX is either a file or a
process
 A process is an executing program identified
by a unique PID (process identifier)
 A file is a collection of data. They are created
by users using text editors, running compilers
etc.
 Example of files: documents, directory, etc.
Basic UNIX
 Most UNIX functionality is accessed through the
UNIX prompt.
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Text based, like MS-DOS
UNIX Directory Structure
 Files are grouped in the directory structure.
The file-system is arranged like hierarchical
tree structure.
 The top of the tree is called “root” which
usually contains several sub-directories.

“/”(forward slash) is used to present the
“root”.
What is Directory?
Directories can hold files and other directories
/
bin
users
etc
root
tmp
backup
usern
user1
user2
……
public_html
file1
index.html
UNIX – Basic commands
 man – manual. Use “man name” to bring up a manual entry for
command or program name.
 clear – clear. Clears the screen.
Navigation
 ls – list. Lists folders/files in a directory
 cd – change directory.
Use “cd name” to navigate to directory name.
 pwd – print working directory. Prints the path of the current
directory.
 du – disk usage. Shows the disk usage of the current directory
Programs
 Some basic UNIX programs:
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emacs – text editing
pico – another text editor
gcc – C compiler
pine – program for internet news and email