MELJUN CORTES computer organization_lecture_chapter14

Chapter 14Working with the Command-

Line Interface

MELJUN CORTESMELJUN CORTES

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OverviewIn this chapter, you will learn to

Explain the operation of the command-line interface

Execute fundamental commands from the command line

Manipulate files and folders from the command line

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Historical/ConceptualIBM invented the PC in the late ’70s but needed

an operating systemDigital Research had an OS but turned them downIBM went to a small company (Bill Gates at

Microsoft) that had created BASICMicrosoft had never written an OS but accepted

the challengeGates found an OS called Quick-and-Dirty-Operating-

System (QDOS) and purchased it from the person who wrote it

Microsoft released it as MS-DOS V 1.1 (Microsoft Disk Operating System)

MS-DOS 6.22 ultimately released in 1994DOS used a command-line interface

Deciphering the Command-Line Interface

IT Technician

CompTIA A+Technician

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Command-Line Interface (CLI)

How does a command-line interface work?Begins with a prompt indicating the computer is

ready to do somethingType in a command and press ENTERThe command is executedA new prompt is displayed—ready for the next

commandCLI executes commands like the Windows GUI

In CLI, type the command and press ENTERIn GUI, point and click to execute commands

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Accessing the Command LineIn Windows 2000 use the Run dialog box

Start | RunType cmd

You may also access the command line through the Start | All Programs menu

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The Command PromptThe command prompt is always focused on

a specific folderAny commands operate on the files and

folders in the folder in which you are focusedYou must first focus on the drive and folder

where you want to work

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Filenames and File FormatsEach program or piece of data is stored as a

file on the driveFilenames have two parts

FilenameIn DOS, up to 8 characters long

ExtensionIn DOS, up to 3 characters longOptional

The filename and extension are separated by a dotCalled the 8.3 naming system

These characters may not be used/ \ [ ] | ÷ + = ; , * ?

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Filenames and FormatsWindows does not restrict the filename to

8.3 (can be up 255 characters)To be backward-compatible with DOS you

need to follow the 8.3 standardWindows creates two filenames for every file

to ensure backward-compatibility

The extension tells the computer the type of file.exe, .doc, .xls

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File FormatsAll files written in binary format

American Standard Code for Information Interchange (ASCII) used for textUniversal file formatDefines 256 8-bit characters

UnicodeUses 16-bit code to cover every character for

the most common languages

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ASCII Character Chart

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Drives and FoldersAt boot, Windows assigns partitions and a

drive letterFloppy drives are usually assigned A: or B:Hard drive partitions may be assigned C: to Z:CD-ROM drives are named after hard drives

Windows uses a hierarchical directory treeFiles are put into groups called folders

In DOS we call folders directoriesThe root directory is at the beginning of the

hierarchical structure with folders underneath

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Folders and FilesFolders and files must be unique

Can’t be the same name in the same folder

C:\ represents the root directory of C

To describe a subfolder, add the name of the folderC:\TEST

The location of a file is called the pathThe path of C:\test\file.txt is C:\test

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Directory Tree

Mastering Fundamental Commands

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Structure: Syntax and SwitchesThe command line requires the exact syntax for

each command

Type the name of the command and desired or allowed switches

Switches modify the behavior of the commandMultiple switches may be allowable

DIR /W /PDisplays the directory in wide mode and one page at a time

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Help

Help with any command is readily available in one of three waysHELP gives a one-line description of each

commandHELP command gives specific help for the

commandCommand /? gives specific help for the

command

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DIR Command The DIR command lists the contents of a

particular directoryThe DIR/W command lists only the filenames

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DIR Command Switches

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Directories: CD Command The CD (or CHDIR) command is used to

change the focus to a different directory

The CD\ command is used to return to the root directory

CD .. Goes up one directory

To switch between drives, type the drive letter followed by a colonC:D:

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Making and Removing Directories The MD (or MKDIR) command is used for

creating a directory

The DEL command is used for deleting files, and the RD (RMDIR) command is used for deleting directories and subdirectories

The DELTREE command is used for deleting directories containing files and subdirectories

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Running a Program To run a program:

Change the DOS focus to the directory where the program is stored

CD C:\Program Files\My Program

Type the filename with or without its extension and press ENTER

Setup.exe

Working with Files

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Working with Files Attributes (H, R, S, A) are special values

assigned to a fileHidden: hides the fileRead-only: protects a file

from being deleted or modifiedSystem: identifies system filesArchive: identifies files that

have not been backed up

The ATTRIB.EXE program is used to inspect and change file attributes

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AttribAttrib can be used to change the attributes

Use + to add attribute- Use – to remove attribute

Attrib +R AILOG.TXT Makes it read only

Attrib –H AILOG.TXT Makes it no longer hidden

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Working with Files Wildcards:

Wildcards are special characters that enable commands to act on more than one file at a time

The * represents any number of charactersThe ? represents a single character

DIR *.TXT Lists all files that end in .TXTDIR *.?XT Lists all files that end in XT

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Working with Files REN command is used to rename filesDEL and ERASE commands are used to delete

filesCOPY command is used for making a copy of

the file in a new locationMOVE command is used for moving the file to

a new locationXCOPY command is used for working with

multiple directories

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Mike’s Five-Step COPY/MOVE Process1. Point the command prompt to the directory

containing the files to be copied or movedC:\> CD \DOCS

2. Type COPY or MOVE and a spaceC:\DOCS> COPY

3. Type the name(s) of the file(s) to be copied/moved and a space

C:\DOCS> COPY *.doc 4. Type the path of the new location for the files

C:\DOCS> COPY *.doc c:\Steam5. Press ENTER

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Working with Batch FilesBatch files are text files that store a series

of commandsOne command on each lineBatch files use the .BAT extensionBatch files may be edited with any text editor

NotepadEDIT

Batch files get their own type of icon

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EDITEDIT is a command-line command that

starts a basic text editor

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Creating a Batch FileUsing EDIT, type in some commands on

their own line (such as cd:\ and Dir)

Save the file with a .BAT extensionC:\test.bat

Launch a command prompt and run the batch fileC:\> CD \C:\> Test.bat

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Additional CommandsSome additional commands are

VER shows the current version of Windows

ECHO tells the batch file to put text on the screen

TYPE displays the contents of a batch file on the screen

SET display settings that Windows has loaded by default

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ECHO CommandECHO will display text on the screen

ECHO OFF turns off the display of text on the screen

@ at the beginning of a line prevents displaying the command, but not the result of the command

@ECHO OFF is frequently used in batch files to “clean up” the appearance when the batch file is run

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SET and PATH CommandsSET will display the list of settings that

Windows loads by default

Programs (and batch files) are run from the location where the prompt isIf the program is not located in the current

folder, you receive an error messageTo tell your command to look in other places,

use the PATH commandPATH by itself lists the current list of places to look for

a programPATH= location; location; location; … will add locations

Beyond A+

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Using Special Keys F1 function key brings back the previous

command one letter at a time

F3 function key brings back the entire command at once

The DOSKEY command stores a list of all previously typed commands and can be accessed by using the up arrow keyType DOSKEYWindows XP/2000 automatically starts the program

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COMPACT CommandCOMPACT

Displays or alters the compression state of files

compact /c

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CIPHER CommandCIPHER

Displays or alters the encryption state of files/e specifies encryption operation/a says to apply it to the files as well as the

directory

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