internal and external commands of DOS file operation

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Use internal and external commands of DOS file operation:-

There are two types of commands in Dos.

• Internal command 
• External command

Internal commands-

This commands, which are automatically loaded into main memory of computer during the booting process. They are actually included in the command. Com file. So these are executable immediately after gating the DOS prompt.

CLS- 
  Syntax-   CLS 
   
  Definition-   This command is used to            clear the screen

 Example-   D:\ TRAINING>CLS

DATE-
            Syntax-    DATE [/T|<date>]
          
          Definition- This command is used            to display or set the system date. 
          Type DATE without parameters to            display the current date setting               and prompt for a new one. Press             ENTER to keep the same date.
      
       /T - Switch which tells the                            command to just output the                        current date, without promoting              for a new date.
 
       <Date> - This is used to give the                 date directly to change the current.

      Example- D:\TRAINING>DATE                    02/03/2005
      D:\ TRAINING>DATE
      D:\ TRAINING> DATE/T

TIME-
               Syntax- TIME [/T| time] 

               Definition- This command is                       used to displays or sets the                         system time.

               Example- D:\TRAINING> TIME 
               D:\TRAINING>TIME/T 
               D:\ TRAINING>TIME 1:30

VOL- 
             Syntax- VOL [drive name:]
         
             Definition- This display the disk               volume label and serial                               number, if they exist.  

            Example- D:\TRAINING>VOL
            D:/TRAINING>VOL A 

VER- 
             Syntax- VER

            Definition- This command is                      used to display the version of the              operating system. 
   
            Example- D:/TRAINING>VER

MD or MKDIR- 
          Syntax- MD <directory name>

             Definition- This command is                     used to create a directory.

             Example- D:\TRAINING>MD                       DIR1

CD or CHDIR- 
         Syntax- CD [..]CD[\] [drive:][path]
   
            Definition- This command is                      used to display the current                        directory name or changes the                  directory.
       
             Example- D:\TRAINING>CDDIR1               ® To go inside the DIR1 directory.
          
           D:\TRAINING\DIR1>CD® To                       display the current directory                     with drive and path

           D:\TRAINING\DIR1>CD                                 D:\DIR1\TEACH® To go inside the            TEACH directory of DIR1                            directory.

          D:\TRAINING\DIR1>CD.. ® TRAINING change the parent directory. Here            STUDENT is the parent directory             of DIR1 directory “C:\STUDENT>”.

        D:\ TRAINING\DIR1> CD\ ® To                    return to root directory I.e. root                prompt “C:\>”.

RD or RMDIR- 

        Syntax-  RD [drive:][path]<directory name>               

Definition- This command is used to remove the current directory.

Note: Before removing or deleting a directory we have remember the followings cautions: 
   
  • The directory must be empty
•The directory must be on the right path
• Control or prompt should not be in the perticular path.
  
Example- D:\TRAINING>RD DIR1® TO remove or erase the DIR1 directory. 

What is directory?

A Directory is a reserve space or memory area in the hard disk of any secondry storage devices, in which we can store files or subdirectories.

Limitation for a naming a directory

• There is no extension name in of directory like incase of file.

• Normally the name can be maximum of 8 characters long.

•  This can be alphabet A-Z, 0-9 or some special characters like “,” (Camas), “/” ( Front Slash), “\” ( Back Slash), “>” (Greater than), ”<” ( Less than), “|“ (piping symbol), started with blank spaces or “.” (Full stop). Or more than one “.” (Full stop) or any space is not allowed in between a name of the file.

Dir- 

 Syntax-  DIR [drive:] [path] [filename] [/A[[:] attributes]] [/B] [/C] [/D] [/L][/N] [/O[[:] sort order]] [/P] [/Q] [/S] [/T[[:] time field]] [\W] [/X] [/4] 

Definition- This command is used to display a list of files and subdirectories in a directory. [drive:][path][filename] spacific drive directory, and or files to list. 

/A   Display files with specific attributes.

Attributes  
      -D Directories  - R Read only files

      - H Hidden files  - A Files ready for            archiving      - S system files 
      -P  Prifix meaning not 

/O    List by files in sorted order.

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