Transcript Command Line Interface

Command Line Interface
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Lecture Objectives
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Explain the operation of the command line
interface
Execute fundamental commands from the
command line interface
Manipulate files and folders from the
command line
How does the Command Line Work?
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Similar to Instant Message conversation with
computer
The prompt indicates that the computer is
ready to receive a command
Command is typed and ENTER is pressed
PC executes command
Prompt is displayed, indicating that the
computer is waiting for the next command
Accessing the Command Line
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Run dialog box
Start menu under Programs | Accessories
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To close command line interface
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Win 9x/Me link is named MS-DOS prompt
Win NT, 2000, XP link is called Command Prompt
Type Exit at command line and press enter
Close the window
Command Prompt
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VERY IMPORTANT:
The command prompt is always focused on a specific
folder.
Any commands executed are performed on the files in the
folder on which the prompt is focused.
Examples: C:\> root directory of C: drive
C:\Diploma\APLUS>
You must focus the prompt on the drive and folder where
you want to work
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Filenames and File Formats
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In Windows, each program and piece of
data is stored as an individual file
Each file has a name, stored with the file
on the drive
Names have 2 parts: filename and
extension
Eight-dot-Three naming system
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File name cannot be more that 8 chrs
Extension can be up to 3 chrs, OPTIONAL
Following chrs cannot be used in
filename or extension:
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/ \ [ ] | = + ; , * ? And division symbol
Windows naming rules
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All versions starting with Win 9x are not
limited be 8.3
Filenames up to 255 chrs
Win 9x has backward compatibility with
DOS by creating 2 names for every file,
8.3 name and a long file name if
necessary
File extensions
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Describes the type or function of the file
COM = command, EXE = executable
Anything that is not a program is a data file used
by a program
Extension of a data file indicates which program
uses that data file
.DOC = MSWord, .PPT = PowerPoint
Graphic file extensions represent the graphic
standard used to create the image
.JPEG =Joint Photographic Experts Group
File Formats
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All files stored on hard drive in binary format
Every program is unique in the way it reads and
writes this binary data
Each unique way of binary organization is known
as a file format
One program cannot read another programs files
unless it can convert the other programs format
Drives and Folders
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To execute commands from the command
line, must focus the prompt at the specific
drive and folder that contains the files or
program with which you want to work
At boot, Win assigns letters to drives and
drive partitions
Hierarchical Directory Tree
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All files are put in groups called folders
Any file not in a folder within the tree is
said to be in the root directory
A folder inside another folder is called a
subfolder
Any folder can have multiple subfolders
Hierarchical Directory Tree
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Hard drive is represented by C:
Root directory is indicated by \, C:\
Subdirectories/Subfolders are indicated
by adding \ and the directory name
Exact location of a file is known as its
PATH
Fundamental Commands
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ALL commands use similar structure and
execute in the same way
Name of command , target of command
followed by any switches (extra numbers
or letters at the end)
Typing the command followed /? Displays
help menu describing syntax and
possible switches
DIR Command
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Contents of the directory where the prompt is
focused
Lists the following:
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Filename
Extension
File size in bytes
Creation date/time
DIR/W command shows you only the file names
DIR/? Shows the help menu
CD Command (Directories)
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Change focus of command prompt to a
different directory
CD\ followed by directory name
If directory does not exist, error message
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Invalid Directory
The system cannot find the path specified
Return to root directory by typing CD\
Moving Between Directories
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CD NOT used to move between drives
Type drive letter followed by colon
If drive does not exist:
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Invalid drive specification
The system cannot find the specified drive
Making Directories
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To make a directory
To make a directory called QUAKE3 under
root directory: C:\>MD QUAKE3, press
ENTER
If command is successfully executed, the
command prompt will be displayed
Use DIR to verify that directory was
created
Removing Directories
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Reverse of MD
Go to directory that contains the
subdirectory you want to delete
Execute RD command
RD will not delete directory if it contains
subdirectories or files
Running a Program
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Change focus of prompt to the folder
where program is located
Type name of program
Press ENTER
Working with Files
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All files have 4 basic attributes:
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Hidden
Read-only
System
Archive
Refer to photocopy for specific example
of attribute command
Renaming Files
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REN or RENAME command (refer to
photocopy for example)
Delete Files
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Use DEL command
Careful! No recycle bin.
Erased file can only be recovered using
Norton Unerase
Can delete multiple files using wild cards
Copying and Moving Files
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Focus prompt on directory containing the
file or folder to be copied
Type COPY or MOVE and a space
Type name(s) of the file(s) to be
copied/moved and a space
Type the path of new location for the files
(Refer to example on photocopy)
The Software Core
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A Short History of MS-DOS
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Understanding DOS
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All versions were built for a specific class of
CPU.
MS-DOS never overcame critical limitations.
All versions used a command-line interface.
You must use the DOS prompt to set up a
new system or hard disk drive.
DOS Boot Sequence and Files
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Three core programs
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Two optional startup files
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IO.SYS
MSDOS.SYS
COMMAND.COM
CONFIG.SYS
AUTOEXEC.BAT
Summary of Steps in Booting the
System
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1. The power-on self test (POST) runs and
invokes the operating system (OS).
2. The read-only memory basic input/output
system (ROM BIOS) looks for an OS and
checks for IO.SYS and MSDOS.SYS.
3. The OS processes CONFIG.SYS, if present.
4. COMMAND.COM is loaded.
5. The OS processes AUTOEXEC.BAT, if
present.
6. COMMAND.COM presents the active-drive
prompt.
The DOS File System
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The file is the primary unit of data storage.
Files are organized into directories.
File and directory names can be up to eight
characters long, followed by a period and a
three-character extension.
Some universal extensions are .exe, .com,
.sys, .bat, .txt, .doc, and .drv.
File and directory names are not casesensitive.
The Evolution of Microsoft
Windows
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Early versions presented a graphical user
interface (GUI) for MS-DOS.
Microsoft Windows 3.11 was the last 16-bit
OS and the most well known version.
Microsoft Windows 95 was the first 32-bit
version.
All applications designed for Windows have
standard interfaces.
Multitasking allows users to have more than
one application open.
Operating Modes
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Real mode could address only 1 MB of
random access memory (RAM).
Standard mode allowed programs to run in
protected mode.
In protected mode, programs could address
up to 16 MB of RAM.
386 enhanced mode could address up to
4 GB of RAM.
Certain applications included a Windows
runtime version.
Windows Resource Management
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Memory Paging and Virtual
Machines
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Virtual memory is an area on the hard disk
drive (called a swap file) that the system
uses to store program code temporarily.
Virtual machines (VMs) allow multiple
programs to operate.
DOS programs run individually in separate
VMs.
Windows Operating Systems
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Microsoft Windows for Workgroups 3.11 is an
upgrade to Microsoft Windows 3.1.
Windows 95, Microsoft Windows 98, and
Microsoft Windows Me can be networked easily.
Microsoft Windows NT is designed for
networking.
Microsoft Windows 2000 replaces Windows NT.
Upgrading to Windows NT or Windows 2000
could present compatibility problems with some
hardware and applications.
The COMMAND Command
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MS-DOS uses a text-based command-line
user interface.
A text-based interface requires no drivers
because display functions are built in.
COMMAND.COM provides the user
interface.
Working with the Prompt
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Typing PROMPT /? or HELP PROMPT
provides help information.
DOS HELP returns information on
customizing the prompt and the information
that appears.
Internal and External Commands
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External commands exist as separate files.
Windows has its own set of system utilities.
Internal commands are contained within
COMMAND.COM.
Command mode requires typing a command
instead of clicking an icon.
DOS Mode Navigation and File
Management
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The DOS file system uses a tree structure.
A fully qualified path is the list of directories
from the root to the file.
The DIR command displays the contents of
the current or a specified directory.
DOS does not support Windows long
filenames.
The MD command creates a new directory.
The PATH Command
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PATH allows you to display and change the
search path.
%PATH% appends the old path to the new
path.
Programs in path directories can be run from
any location on the computer.
Creating a Batch File
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A batch file is an executable file that runs a
series of existing commands or applications.
Commands listed in the file are executed in
sequence.
Any executable that can be run from the
prompt can be included in a batch file.
Renaming a File
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The RENAME or REN command allows you
to rename a file.
The CD command allows you to change
directories.
The CLS command clears the screen.
Using Edit
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Summary of DOS Terminology
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CONFIG.SYS Commands
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BUFFERS
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FCBS
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MOUSE.SYS
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COUNTRY
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FILES
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NUMLOCK
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DEVICE
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INSTALL
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SHELL
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DEVICEHIG
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LASTDRIV
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SWITCHES
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DOS
AUTOEXEC.BAT Commands
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DOSKEY
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PATH
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SET
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ECHO
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PAUSE
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SHARE
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KEYB
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PROMPT
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SMARTDRV
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MOUSE.EX
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File System Basics
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The file system organizes data on the
storage medium.
Different media require different file systems.
File systems define naming conventions, file
size, and media capacity.
Magnetic media employ several different file
systems, depending on the OS.
Key File System Terms
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Block
Boot disk
Boot sector
Cluster
Dual boot
Encryption
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End-of-file
(EOF)
marker
File
File
allocation
table (FAT)
File format
File handle
File locking
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Filename
Folder
Format
Low-level
format
Master boot
record
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Partition
table
Primary
partition
Sector
Track
Volume
Comparing and Choosing File
Systems
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Decision factors:
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Dual boot requirement
Number and size of hard disk drives
Size of partitions
Need to support legacy applications
Need for advanced features such as security
FAT-Based File Systems
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All modern PCs can use FAT.
FAT organizes files by listing them in a table.
Two copies of the table are maintained on
the media.
FAT was developed for and is still used by
floppy disk drives.
There are three versions: FAT12, FAT16, and
FAT32.
FAT16 and FAT32 Compared and
Contrasted
FAT16
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High compatibility
Use of MS-DOS bootable floppy
disk
Performance advantage on
small volumes
Manual intervention to use FAT
copy
No backup of boot sector
2-GB volume limit
Better performance when
operating in real mode or safe
mode
Dual boot with Windows NT and
Windows 98
8.3 filenaming limit
FAT32
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Limited compatibility
No use of MS-DOS bootable
floppy disk
More efficient allocation of disk
space
Automatic use of FAT copy if
needed
Automatic backup of boot sector
Support of 32-GB volumes
Faster load times for
applications and large data files
No dual boot with Windows NT
and Windows 98
Support of filenames up to 255
characters
The NT File System (NTFS)
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Was introduced with Windows NT
Supports long filenames and is optimized for
multiuser environments
Provides file and folder level security
Is more reliable than previous file systems
Is not completely supported under Windows
NT
Advantages and Disadvantages of
NTFS
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Advantages
Supports volumes up to
2 terabytes (TB)
Maintains a recovery log
Has no limit on number of
entries at root
Allows faster file access
Supports disk quotas (Windows
2000)
Supports file and folder
compression
Supports file and folder security
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Disadvantages
Does not allow accessing NTFS
volumes under MS-DOS,
Windows 95, or Windows 98
Does not allow using NTFS
volumes as a primary partition
for dual booting MS-DOS,
Windows 95, or Windows 98
Could decrease performance on
volumes smaller than 400 MB
File System Size Limitations
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Different OSs handle cluster size differently.
Under FAT volumes, drives smaller than
16 MB are formatted as FAT12.
MS-DOS, Windows 95, and Windows 98
cannot access FAT16 volumes larger than
2 GB.
File System Security
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FAT attributes on FAT file systems
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NTFS file and folder security
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FAT has attributes that can protect files from
being overwritten or viewed.
Attributes can be set by using the ATTRIB
DOS-mode command, or by right-clicking a file in
Windows and selecting the Properties option.
NTFS uses permissions to determine who can
access the file or folder.
Permissions are set by using the Security tab for
the file or folder.
Chapter Summary
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An OS is the interface between the hardware and the
user.
All OSs have a user interface, memory, and file
management.
Technicians need to know how to perform command
prompt operations.
Technicians who work with older OSs must
understand MS-DOS and DOS startup files.
Internal and external commands can be used to
configure and troubleshoot.
FAT32 has several enhancements over FAT16.
NTFS supports file and folder security, compression,
and disk quotas.