DOS COMMANDS

DISK OPERATING SYSTEM (DOS)

INTRODUCTION

DOS is an Operating System. It works as an interpreter between user and computer. We give

English like commands and it converts it into machine language and after the computer has

processed the information, returns the results to you in English. Ms. Dos consist of four essential

programs and a set of additional utilities.

Components of MS-DOS

MS-DOS consists of four essentials programs and a set of additional utilities. Four main

programs are

·          Boot Record

·          IO.SYS

·          MSDOS.SYST

·          COMMAND.COM

Booting: Process that starts up a computer is called booting. It checks for proper functioning of

all the peripheral devices attached with the system. It searches for the operating system and,

when located, loads it into the main memory. See fig.01.

Cold Booting is done by turning on the computer.

Warm Booting is performed by pressing Ctrl+Alt+Del keys simultaneously.

There are two name in DOS and is divided into 2 parts.

1. Primary Name

2. Secondary or extension.

Primary name is separated from the Secondary name extension with the help of a dot (.) look at

the following example.

Example: ENVOICE. TXT

Primary name can be from 1 to 8 characters long and

Secondary name contains 3 or less than 3 characters and is optional. The extension tells DOS

about what kind of file it is.

A valid Character for naming a file are: from A to Z and the digit 0 to 9

C :\> Is known as DOS/command prompt, where we give the commands.

DOS command divided into 2 parts.

1. Internal Commands or Memory-Resident Commands

2. External Command or Disk-Residence Commands

INTERNAL COMMAND

There are also called memory-resident commands. These commands are automatically loaded

into the computer’s memory during the booting process. They actually included in the

Command.com file. So these commands are executable immediately after getting the dos

prompt.

A few internal commands are

01. VER

02. VOL

03 DATE

04. TIME

05. CLS

06. DIR

07. MD

08. CD

09. PATH

10. RD

11. COPY CON

12. TYPE

13. COPY

14. DEL

15. REN

16.PROMT

A command can be given in Capitals or Small letters also. The internal commands can

execute immediately but External Commands require special files for their execution

without which it is not possible to execute them.

1. VER: - All O/S has its own edition number or release or version number. The version

number indicates which edition of O/S you are working on.

Syntax:    VER <Enter>

Example:    C:\> Ver <Enter>

output: -  Microsoft Windows XP [ Version 5.1.2600]

02. VOL: - It is used to display volume label and serial number of the current drive

Syntax:  Vol [drive:]

Arguments:

·               Drive: This command-line argument specifies the drive letter of the disk for which to display the volume label and serial number.

Example:  C:\> VOL c:

Output:

C:\Users\root>vol C:

Volume in drive C is Vista

Volume Serial Number is 080F-100B

3. DATE: - Used to display the current system date and prompt for entering new date.

DATE is a command in DOS, OS/2 and Windows. This command is available in command line interpreters (shells) such as COMMAND.COM, CMD.EXE, 4DOS, 4OS2 and 4NT.

 

Syntax

The syntax differs depending on the specific platform and implementation:

DOS

DATE 

This command will display the date and wait for the user to type a new date and press RETURN

Windows (CMD.EXE)

 DATE [/T ]

The parameter '/T' will bypass asking the user to reset the date.

The format of the date parameter is dependent upon regional settings.

DATE [/T] [mm-dd-yy]

/T:  (Display only)

mm:  The month (1–12).

dd:  The day (1–31).

yy:  The year (00–99, or a 4-digit year).

Examples :

·         To display the system date and prompt for entering new date.

[C:\]DATE

Current date is: Wed  2.12.2010

Enter the new date: (dd.mm.yy)

·         To display the current system date without prompting for entering new date.

C:\>DATE /T

11.16.82

4. TIME: - Displays the current system Time and prompt for entering new time.

·         To display  the current system Time and prompt for entering new time with the format hh:mm:ss:xx.

hh:hours

mm:minutes

ss:seconds

xx:100^th of the second

Syntax:   C:\> Time

Output:

 The current time is : 15:59:08:18

Enter the new time:_

 Either type a new time and press enter

 or press enter without typing any time to leave the same time

·         To display the current system Time without prompting for entering new time.

Syntax: :          C:\> Time  /T

Output:            03:59  PM

5. CLS: - Clears the screen.

Syntax: CLS <Enter>

Example: C:\> CLS <Enter>

6. DIR: - This command displays the list of directories and files with details like date of

creation whether it is directory or file etc.

Syntax: C:\> DIR

Switches:

/p : To view one screen of files at a time.

/w : Displays only five column of filenames and directories.

/b : Display only file and directory.

/l : Display all the information in lower case letters.

/a — stands for attributes that are given below.

/-h - Hidden ( or not hidden) files

s/-s - System ( or not systems) files

d/-d - Directory ( or not Directory) names

r/-r - Read only( or not read only) files

Example:

C:\>DIR

output:

 Volume in drive C has no label.
 Volume Serial Number is 8C87-FFA1

 Directory of C:\

04/21/2006  04:42 PM    <DIR>          Batch
04/18/2006  12:06 AM                 0 CONFIG.SYS
04/21/2006  07:45 PM                 32 dir.txt

 2 File(s)             32 bytes
               3 Dir(s)  196,047,323,136 bytes free

C:\>DIR *.txt                                         Display all the files with extension .txt

C:\>DIR D???.*                                  Display all the files starting with D and

                                                               having less than or equal to four characters

                                                             in the file name and any extension.

Here “?” And “*” are called “wild card character”.

“*” Stand for any number of the character

“?” Stands for nay one character.

07. MD OR MKDIR: -Used to create a new Directory or nested Directories.

Syntax:    MKDIR OR MD [DRIVE:] PATH DIRECTORY NAME

Example: C:\> MD SAMS

08. CD OR CHDIR: - This command allows you to change present directory to another

directory.

Syntax: CD [DRIVE:] PATH

Example: C:\> CD SAMS

8). CD or CHDIR  (Change Directory) is an internal command used to switch between directories in MS-DOS

Syntax

Windows XP and later

CHDIR [/D] [drive:][path]
CHDIR [..]
CD [/D] [drive:][path]
CD [..]

..                   Specifies that you want to change to the parent directory.

 [ drive:]       to display the current directory in the specified drive.
 CD               without parameters to display the current drive and directory.

 /D                switch to change current drive in addition to changing current directory for a drive.

Windows 98 and earlier syntax

CHDIR [drive:][path]
CHDIR[..]
CD [drive:][path]
CD[..]

Examples

cd\

               Goes to the highest level, the root of the drive.

cd..

               
               Goes back one directory.
                For example, if you are within the C:\Windows\COMMAND> 
                directory, this would take you to C:\Windows>

 Summary:

CD..   (Work your way down a path)
CD\    (Take you right to the root of the drive)
CD NameOfDirectory\NameOfSubDirectory    (Work your way up a path)
CD     (When used on its own it just displays the current path)

Switching Between Drives
This is very easy as all you have to do at the Command Prompt is type the following and press "Enter"

D:   (After typing D: press the "Enter" key to switch to D Drive)
E:   (After typing E: press the "Enter" key to switch to E Drive)
F:   (After typing F: press the "Enter" key to switch to F Drive)
C:   (After typing C: press the "Enter" key to switch back to C Drive)

09. PATH: - This command defines a list of directories DOS Searches for external

            commands.

PATH [ [drive:] path[;...] ]

PATH ;

Type PATH ; to clear all search-path settings and direct DOS to search

only in the current directory.

Type PATH without parameters to display the current path.

10. RD: - To delete the empty directory.

Syntax: RD [DRIVE:] PATH

NOTE: -The directory must be empty when we use RD.

Example: C:\> RD SAMS

Switches: - 1.          /s – Remove with subdirectories and files.

      2.          /q – Don’t ask to confirm.

11. COPY CON: -We use this command to create a new file.

Syntax: COPY CON  <FILENAME>

Example: C:\> Copy Con sams.txt

Note: - Typing here and when you are done, press Ctr+Z or F6 key followed by Enter to

save the current document.

12. TYPE: - This command allows you to see the contents of an existing file on the

screen.

SYNTAX: TYPE [DRIVE: ]  [PATH] <file name>

  [DRIVE: ]    Specifies the drive the file is stored

[PATH]           Specifies the path of the file

<file name>  Specifies the name  of  the file

Example: C:\> TYPE SAMS

13. COPY: - Using this command we can make duplicate files of an exiting file from one

location to another or one directory to another with different name or exiting name.

SYNTAX:

C:\> COPY  < SOURCE FILE NAME>  <TARGET FILENAME>

 C:\>COPY [/A | /B] source [/A | /B] [+ source [/A | /B] [+ ...]] [destination [/A | /B]] [/V] [/Y | /-Y]

  source       Specifies the file or files to be copied.

  /A           Indicates an ASCII text file.

  /B           Indicates a binary file.

  destination  Specifies the directory and/or filename for the new file(s).

  /V           Verifies that new files are written correctly.

  /Y           Suppresses prompting to confirm you want to overwrite an

               existing destination file.

  /-Y          Causes prompting to confirm you want to overwrite an

               existing destination file.

The switch /Y may be preset in the COPYCMD environment variable.

To append files, specify a single file for destination, but multiple files

for source (using wildcards or file1+file2+file3 format).

/Y and /-Y are only available in DOS 6 and above.

Example: C:\> COPY SAMS.TXT A:\TAJ

Example: C:\> COPY*.TXT +*.BAK TARGET FILENAME And Then Press Enter

Example: C:\> COPY SAMS.TXT C:\SAMS_1\FO\RECEPTION And Then Press Enter

You can also have the option to change the name of files as you copy it.

Example: C:\> COPYold.TXT C:\dos\new.txt And Then Press Enter

14. DEL / ERASE: This command removes one or more files from the disk or current

working directories.

SYNTAX:   DEL filespec [/p]  [/q] or ERASE filespec [/p] [/q]

Example:   C:\> DEL C:*.BAK /P And Then Press Enter

Example:   C:\> DEL abc And Then Press Enter

Example:   C:\> DEL ????.COM And Then Press Enter

Switches:      filespec    Specifies the file name

         /p              confirmation

                      /q               In quit mode

15. REN: Used to change the name of the file or directory.

SYNTAX: REN <file name>

Example: REN sams sams1 <Enter>

Example: REN *.dat *.mst And Then Press Enter

16 PROMPT: This command allows you to customize the dos prompt.

SYNTAX:   PROMPT

 Some special $ parameters are given below.

Character                     example description

$Q                   = Equal Sign

$$                    $ Dollar Sign

$t                     12:30:06:92 Display current time

$d                    tue 09-07-2007 Display current date

$v                    msdos version 6.2 show dos version number

$g                    > Greater than sign

$L                    < Less than sign

Most people like to set their prompt to $p$g which display the current directory followed

by > sign.

Example: PROMPT $P$G <Enter>

17. TREE: - It is used to display directory structure of a specified directory graphically.

Syntax : TREE [drive:] [path] [/f]

[/F] : displays the names of the files in each directory.

EXTERNAL COMMAND:

These are also called Disk-Resident Commands. These commands are meant for

special purpose. These are found in separate files on Hard Disk or Floppy Disk, So that

they don’t typically consume valuable memory space. They are loaded into memory only

when called.

Some External Command are:

1. Xcopy

2. Move

3. FC

4. Doskey

5. Mem

6. FILTER

   a.. More

   b.. Sort

   c Find

7 Attrib

8. Deltree

9 Edit

10 Tree

1. XCOPY:  This command is faster than Copy Command and allows you to copy

entire directories/disk including all the sub directories and files to destination.

Syntax:         XCOPY Source [ Target][/Y][-Y] [/P][/E]

SWITCHES :

/-Y : Prompts before copying over existing files.

/y : Overwrites existing files without prompting.

/p : Ask before copying each file.

/e : Copying empty directory also.

/s : Copying subfolders.

EXAMPLE:   XCOPY   C:\SAMS   D:\SAMS /S/E

2. MOVE : This command moves a file or group of files from one directory to

another and also one disk to another disk. It can also be used to rename directories.

SYNTAX: Move [Path File Name] [Destination file name path]

SWICHES:

/-Y : Prompt before it overwrites while it copies file that already exists.

/Y : Overwrites existing files without prompting.

EXAMPLE: move c:\sams\fo.txt to d:

EXAMPLE: move c:\sams\fo.txt to d:\ new_sams

3. FC: Stands for File Compare. Compares two files or two sets of files.

           This command has the capability to differentiate between the files and display the

            difference

SYNTAX: FC  <files spec 1>  <files spec2>  [/a] [/b] [/c] [l] [/n]

Switches

/a : This switch displays only the first and last line of each group.

/b : Compare the files in library mode ( byte-by-byte)

/c : Ignore the case of letters.

/l : Compare the files in text mode.

/n : Displays the line number for lines that are different.

EXAMPLE: FC first.txt second.txt\n and then Press <enter>

4. DOSKEY: Dos can remember only the last command you had entered. But in order to

make DOS remember all the commands you enter you will have to load a DOSKEY

utility. Also DOSKEY is Used To Create Macros

Syntax: DOSKEY and Press <Enter>

Display message on the screen.

DOSKEY Installed.

NOTE: - To display all commands from the history list on the screen.

Example: DOSKEY / History or /h < Enter>.

Now when DOSKEY is in memory, it can help store all the commands which you

enter so that any of those commands need not be typed again to be executed.

And this list is called HISTORY LIST. Now when you want the same command to

be done you can use up, down  arrow key or ‘F1’ or ‘F3’ Issuing following command.

Second feature of DOSKEY is Doskey Macro. Using this macro you can create own

command and latter you can run it on the system prompt. For example

EXAMPLE: - DOSKEY C= CLS

Now if you type at the system prompt only C and press enter it will clear the screen.

Recalling Commands: Some key is provided to recall recent commands you have run

since installing DOSKEY.

Key Strok              Effect

Up Arrow              Display the Preceding Command and further list.

Down Arrow        Show the next command you executed after the one that’s being

                             displayed.

Page Up                Display the oldest command that is still in Doskey.

Page Down           Show the most recent command that you executed

F7                    Display the entire list of command that you executed.

F9                    Selects a commands

Alt+F7            Erase the command history list.

Alt+F10          Erase all macros in memory

Esc                  Clear the command line.

Ctrl-T              Command separator

5. MEM:

This command displays amount of total available memory ( low, Expanded and

Extended) and all currently programs.

Syntax: MEM [/f] [/p] [/m]

Switches:

/f      : Using this switch MEM display all the areas of memory that are free.

/p      : Display the information one screen at a time.

/m     : Display information about how a specified program is using memory.

Example: MEM /p and then press <Enter>

6. FILTER:

A Powerful feature of DOS is its use of filters to process data directly. A DOS FILTER

can process in unique way any data that passes through it and can change what we see

on the screen.

There are three FILTERS include in DOS.

A. MORE: More command used to pause vertical Scrolling on the display screen,

after each screenful.

The display pauses and the message - - More - - appears.

Pressing any key display the next screen.

EXAMPLE: C:\> MORE < TYPE FILE.TXT and then press <Enter>

EXAMPLE: C:\> DIR /MORE and then press <Enter>

B. SORT: Reads, Sorts in Order and sends the data to the screen, file or to another

device. Sort to arrange data in an order.

SYNTAX:  SORT  [drive:] [Path] [filename] [/r] [+n]

Switches:

[drive:][Path][filename] : Specifies the name and location of the file to be

                                          searched. It must be preceded by the redirection

                                         character (<).

[/r]            : Sort lines in reverse ASCII Order ( Z-A)

[+n]           : Sorts line starting with the contents in column n. The default is 1.

EXAMPLE: C:\> SORT < NAME .TXT and then press <Enter>

EXAMPLE: C:\> SORT /+20 < PHONE .TXT and then press <Enter>

Note: Sort command doesn’t distinguish between upper and lower case. It can sort file

of maximum 63 k size.

Combining Input & Output redirection :

EXAMPLE: C:\> SORT < NAME .DAT > SORTNAME.DAT and then press <Enter>

Here the sort command is being directed to take its input from <name.dat and after

sorting, send its output to the > sortname.dat file.

C. FIND: The find Filter is used to search a file one or more designated character (called

a text string) Depending upon the form of the FIND Command. Each line having (or not

having) the text string is sent to an output devices, such as the Screen, a file or the

printer. The text string is always typed within quotes ( “Text Sring”).

SYNTAX: FIND [/v][/c][/n] “String “ [d:] [path][filename]

Switches:

[/v]   : Displays all the lines that do not contain string.

[/c]   : Display the total number of lines found to contain the string.

[/n]   : Display the line number as well as the line that contains the string.

[/i]   : Ignores uppercase or lowercase during the search.

Where:

  “String” : Specifies one or more alphabet or numeric character whose maximum

   length should not be more than 250 characters and must be enclosed in double   

   quotes.

[d:] [path][filename] : Specifies the name and location of the file to be searched .

EXAMPLE: C:\> FIND “Rajni” my.txt per.txt and then press <Enter>

7. ATTRIB:

Every File on the Disk has its own description like size, space occupied, the type, the

date it was created, etc. Likewise, every file has few attributes. The attributes of a file

indicates whether it is a

i) Read-Only File: r ii) Archive File a

iii) Hidden File: h iv) System File s

With the ATTRIB command you can check the attributes of a file.

SYNTAX: ATTRIB [+r][+a][+h][/+s] [filename]

Switches:

+r, -r    : +r Read-Only attribute or, -r turn of Read-Only attribute

+a,-a    : +a archive attribute, or -a turn of archive attribute

+h,-h    : +h hidden attribute, or –h turn of hidden attribute

+s, -s    : +s system attribute and it should not be used generally.

Note:

While Creating a new file every file gets read only attribute and archive attribute by default.

EXAMPLE: C:\> ATTRIB   my.txt +R    and then press <Enter>

EXAMPLE: C:\> ATTRIB   my.txt +H    and then press <Enter>

8. DELTREE:

This command used for deleting an entire directory whether in that directory contains

files or subdirectories and also it will delete hidden files.

Syntax: DELTREE [drive:][path] directories [/y]

EXAMPLE: C:\> DELTREE my.txt and then press <Enter>

9. EDIT:

This is the DOS Editor, which you can use to edit the text file and also creating new file.

Syntax: Edit [drive:][path][filename]

EXAMPLE: C:\> EDIT   c:\sams\FO.TXT    and then press <Enter>

EXAMPLE: C:\> Edit  NEW FILE     and then press <Enter>

10. TREE

Allows the user to view a listing of files and folders in an easy to read listing.

Syntax

         TREE  [Drive:] [\ Path] [ /f]

Drive:\Path	Drive and directory containing disk for display of directory structure.
/f	Displays file names in each directory.

Examples

C:\> tree

List a tree listing of the current drive. Below is a basic example of what a directory may look like.

C:.
├───Common
├───Director
├───Flash
├───Shockwave 8
│ ├───DswMedia
│ ├───Prefs
│ └───Xtras
└───update

BATCH FILES

It is a collection of DOS commands to perform a certain task. or A batch file is nothing

but sequence of commands to perform sequence of operations step by step without user intervention.

Look at the following commands you give step by step to perform an operation.

Suppose your job is

First - Check the directory

Second - Copy a file called ABC.txt to another disk

Third - Delete ABC.TXT from the present disk

Fourth - Clear the screen

 

i) C:\> DIR <Enter>
ii) C:\> COPY C:ABC.TXT D: <Enter>

iii) C:\> DEL ABC.TXT <Enter>
iv) C:\> CLS <Enter>

 

How to create a batch file:

C:\> COPY CON A.bat <Enter>

Note:

Here Con means Console that is Keyboard, A the file name and .bat is extension.

It is compulsory that a batch file must have extension .BAT.

You will find the cursor below ‘A’ now type

C:\> DIR <Enter>

C:\> COPY A.TXT D : <Enter>

C:\> DEL A.TXT <Enter>

C:\> CLS <Enter>

Now Press the F6 or Ctrl+Z key combination. You shall find ^Z symbol below CLS, Now

press Enter. You will receive the following message

1files Copied.

And you are returned to the prompt C:\>

Now to execute the Batch File simply type the name of the file.

C:\> A <Enter>

You will see all the commands in the file A.bat come right into action. So instead of typing

all those command one after another performed the same job by just typing the file

name A.