Explain about ‘Microsoft Disk Operating System’ (MS-DOS).
MS-DOS is one of the most popular operating systems. Let us now have a look at some important MS-DOS commands.
The command prompt : When you first turn on the computer, you will see some cryptic information flash by. When the information stops scrolling past, you will see the following :
C:\>
This is called command prompt. The flashing underscore next to the command prompt is called the cursor. The cursor shows where the command you type will appear. DOS commands can be entered and executed one at a time from the DOS prompt. The commands can be typed either in lower case or upper case. You must press 'enter' key after every command you type.DOS commands are basically two types. They are --
A) Internal Commands : These are a few special commands that are automtically loaded into the computer memory when the system is booted. Some important internal commands are listed below :
B) External commands : These are some of the DOS commands that are stored as files on the DOS system disk.
Some important and commonly used commands are briefly explained below:
1. DIR (Directory) : Displays a list of the files and subdirectories that are in the directory you specify. When used without parameters or swithces it gives the particulars such as file extension, file size in bytes, date and time the file was last modified, total number of files listed, their cumulative size and free space remaining on the disk.
2. MD or MK DIR (MAKE DIRECTORY) : Used to create another directory in the drive in which we are working presently.
3. CD (CHANGE DIRECTORY) : We can switch over in to another directory from the present directory with the help of this command.
4. TYPE : With the help of this command we can view the contents of a file.
5. REN (RENAME) : Used to change the name of a file.
6. DEL (DELETE) & ERASE : to delete unwanted files from the directories this command is used. This command can be used in the following way.
7. RD or RMDIR (REMOVE DIRECTORY) : Used to remove the directory permanently from the computer. Syntax at the prompt is : RD . However, before removing the directory, all the files in the directory have to be deleted by using del or erase command. Then only the RD command works and removes the directory from the computer.
8. COPY : This is one of the most useful commands. To copy a file from one place to another place this command is used. Also used to store files on to floppy disks.
9. DATE and TIME : These commands are used to see the current date and time. The date and time can also be changed using these commands if necessary.
10. FORMAT : Creates new root directory and file allocation table for the disk. It can also check for bad areas on the disk and it can delete all data on the disk.
11. UNFORMAT: Restores a disk that was erased by using ‘Format’ command.
12. DISKCOPY : Copies the entire contents of one floppy disk to another floppy disk. Diskcopy writes over the existing contents of the destination disk as it copies the new information to it.
13. XCOPY : Copies directories, their subdirectories and files except hidden and system files. With this command, you can copy all the files in a directory including the files in the subdirectories of that directory. XCOPY source [destination]
14. SORT : Reads input, sorts data and writes the results to the screen, a file or another device. SORT acts as a filter reading characters in a specified column and rearranging them in ascending or descending order.
15. TREE : Graphically displays the structure of a directory.
16. EDIT : Starts MS-DOS editor, a text editor which is useful to create and edit ASCII text files. MS-DOS editor is a full screen editor that allows you to create, edit, save and print ASCII text files.
17. DELTREE : Deletes a directory and all its files and subdirectories.
18. FIND : Searches for a specific string of text in a file or files.
19. HELP : Starts MS-DOS help.
20. MOVE : Moves one or more files to the location you specify. Can also be used to rename files and directories.
21. PATH : Indicates which directories MS-DOS should search for executable files (programs).
22. PRINT : Prints a text file.
23. SCANDISK : Checks disks for damage and repairs them, if needed.
24. DEFRAG : Recognises the files on a disk to optimise disk performance. (This command shall not be used while you are running Windows .)
25. CLS : Clears the screen.
