Operating System Operating System FundamentalsFundamentals

1.1. Components of an OSComponents of an OS

2.2. Functions of an OSFunctions of an OS

3.3. Types of OSTypes of OS

4.4. Command-line toolsCommand-line tools

The Three Elements of an OSThe Three Elements of an OS

User Interface – The part of the OS that User Interface – The part of the OS that you interface with.you interface with.

Kernel – The core of the OS. Interacts Kernel – The core of the OS. Interacts with the BIOS (at one end), and the UI with the BIOS (at one end), and the UI (at the other end).(at the other end).

File Management System – Organizes File Management System – Organizes and manages files.and manages files.

Operating System FunctionsOperating System Functions

File ManagementFile Management

Application ManagementApplication Management

Built-in Utility ProgramsBuilt-in Utility Programs

Control of Computer HardwareControl of Computer Hardware

Operating System TypesOperating System Types

Multiuser – Two or more users work Multiuser – Two or more users work with the computer at the same timewith the computer at the same time

Multitasking – Two or more processes Multitasking – Two or more processes running at the same time.running at the same time.

Multithreading – Two or more parts of Multithreading – Two or more parts of the same process running at the the same process running at the same time.same time.

PC Operating SystemsPC Operating Systems

Microsoft WindowsMicrosoft Windows MacIntosh OSMacIntosh OS LinuxLinux

MS Windows VersionsMS Windows Versions

Home (Non-Professional) VersionsHome (Non-Professional) Versions• Windows 95Windows 95• Windows 98Windows 98• Windows MeWindows Me

Professional (Business) VersionsProfessional (Business) Versions• Windows NTWindows NT• Windows 2000Windows 2000

The Two Lines Came Together in The Two Lines Came Together in Windows XP (2001)Windows XP (2001)

Disk Operating SystemDisk Operating System( DOS )( DOS )

The first PC Operating System (1981)The first PC Operating System (1981) Not a Multitasking OS, only one program Not a Multitasking OS, only one program

could run at a timecould run at a time A command-line interface, no GUI.A command-line interface, no GUI. Early versions of Windows sat on top of DOS Early versions of Windows sat on top of DOS

and used it to communicate with the BIOS.and used it to communicate with the BIOS. Windows XP communicates directly with the Windows XP communicates directly with the

BIOS, but allows commands to be entered via BIOS, but allows commands to be entered via a command prompt.a command prompt.

File SystemFile System

A A filefile is a collection of bytes of is a collection of bytes of information treated as a single unit.information treated as a single unit.

It is given a It is given a namename to make it easy to to make it easy to find and use later.find and use later.

The The file systemfile system keeps track of where keeps track of where a file is actually resident on a disk.a file is actually resident on a disk.

A disk (hard disk, floppy, optical disk) A disk (hard disk, floppy, optical disk) is subdivided into is subdivided into directoriesdirectories or or foldersfolders..

File System (continued)File System (continued) The top level folder on a disk is The top level folder on a disk is

known as the known as the rootroot.. The root is generally subdivided into The root is generally subdivided into

subfolderssubfolders.. Any folder or subfolder can contain Any folder or subfolder can contain

files and other folders.files and other folders. The The fully-qualified filenamefully-qualified filename includes includes

the name of the file and the the name of the file and the pathpath to to the folder in which it resides:the folder in which it resides:

c:\courses\061\cit141\chapter4.pptc:\courses\061\cit141\chapter4.ppt

Windows Registered File TypesWindows Registered File Types

A particular file extension can be A particular file extension can be registeredregistered and and associatedassociated with a particular with a particular program.program.• .docx files are associated with MS Word.docx files are associated with MS Word• .xlsx files are associated with MS Excel.xlsx files are associated with MS Excel• .txt files are associated with Notepad.txt files are associated with Notepad• .html files are associated with IE.html files are associated with IE

This is how Windows knows what to do This is how Windows knows what to do when you double-click a file in My when you double-click a file in My Computer.Computer.

File AttributesFile Attributes Each file has four attributes which Each file has four attributes which

can be viewed or set.can be viewed or set.• Read Only – File may be viewed, copied, Read Only – File may be viewed, copied,

executed (if appropriate), but not executed (if appropriate), but not changed. It can be deleted.changed. It can be deleted.

• Hidden – File will not be displayed in Hidden – File will not be displayed in normal list of files.normal list of files.

• System – File is identified to belong to System – File is identified to belong to system, should not be messed with.system, should not be messed with.

• Archive – File is (or is not) a candidate Archive – File is (or is not) a candidate for backup.for backup.

DOS CommandsDOS Commands

Two types – Internal and ExternalTwo types – Internal and External• Internal commands are resident in the Internal commands are resident in the

main kernel file: command.com (or main kernel file: command.com (or cmd.exe)cmd.exe)

• External commands are separate little External commands are separate little programs.programs.

It's important to learn DOS It's important to learn DOS commands because you can write commands because you can write scripts to execute a set of commands scripts to execute a set of commands automatically.automatically.

The Command PromptThe Command Prompt

By default, it reminds you of the current drive and the current directory.

Three Parts of a DOS CommandThree Parts of a DOS Command

xcopy /m/e c:\temp d:\temp

Command Name

Switches Parameters

DOS Wildcard CharactersDOS Wildcard Characters The characters ? and * can be used The characters ? and * can be used

to affect multiple files with a single to affect multiple files with a single command.command.• The ? means any single character.The ? means any single character.

copy c:\temp\notes??.doc d:\tempcopy c:\temp\notes??.doc d:\temp

means copy any Word file that begins means copy any Word file that begins with the word "notes" with exactly two with the word "notes" with exactly two other characters, like "notes01.doc", other characters, like "notes01.doc", "notesAB.doc", etc."notesAB.doc", etc.

DOS Wildcard CharactersDOS Wildcard Characters

• The "*" wildcard replaces any number of The "*" wildcard replaces any number of characters.characters.

copy c:\temp\notes.* d:\tempcopy c:\temp\notes.* d:\temp(copy all files with the name "notes" and (copy all files with the name "notes" and any extension.)any extension.)

copy *.doc c:\tempcopy *.doc c:\temp(copy all files with a "doc" extension in (copy all files with a "doc" extension in the current directory.)the current directory.)

At the Command PromptAt the Command Prompt A drive letter and a ":" (e.g. "f:") A drive letter and a ":" (e.g. "f:")

makes that your current drive.makes that your current drive. CD (Change Directory)CD (Change Directory)

• cd (with no parameters) reminds you cd (with no parameters) reminds you what the current directory is.what the current directory is.

• cd .. moves you to the parent of the cd .. moves you to the parent of the current directory (up one level).current directory (up one level).

• cd \ moves you to the root of the current cd \ moves you to the root of the current drive.drive.

• cd <some directory> makes that your cd <some directory> makes that your current directory.current directory.

DOS CommandsDOS Commands MD – Make directory.MD – Make directory. RD – Remove a directory or an entire RD – Remove a directory or an entire

directory tree.directory tree. DIR – Display the contents of a directory.DIR – Display the contents of a directory. DEL (or ERASE) – Deletes one or more DEL (or ERASE) – Deletes one or more

files.files. COPY – Places a copy of file(s) in a COPY – Places a copy of file(s) in a

different folder.different folder. XCOPY – Flexible copy command used for XCOPY – Flexible copy command used for

copying large groups of files, commonly copying large groups of files, commonly used for file backup.used for file backup.

More DOS CommandsMore DOS Commands

MOVE – Moves file(s) from one folder MOVE – Moves file(s) from one folder to another.to another.

REN(AME) – Renames file(s).REN(AME) – Renames file(s). ATTRIB – Displays or sets file ATTRIB – Displays or sets file

attributes.attributes. FORMAT – Formats a disk.FORMAT – Formats a disk. CHKDSK – Tests the file system on a CHKDSK – Tests the file system on a

disk, and reports status.disk, and reports status.

Even MoreEven More

DATE and TIME – Display & set the DATE and TIME – Display & set the current date & time in the PC.current date & time in the PC.

TYPE – Displays the contents of a TYPE – Displays the contents of a text file.text file.