DOS (OS)

 DOS (Disk Operating System):

➧ One of the system software that manage the resource and operating (system management).

➧ Single user, single tasking operate on low /less memory.

Types of command:

1. Internal command: The command reside internal memory (RAM), single file, basic operation, source is command.com.

1. ASSOC: Change file extension associations.
2. CALL: Call one batch program from another.
3. CD: Change directory - move to a specific folder.
4. CLS: Clear the screen.
5. COLOR: Change colors of the CMS windows.
6. COPY: Copy one or more files to another location.
7. DATE: Display or set the time.
8. DEL, ERASE: Delete one or more file.
9. DIR: display a list of files and folder.
10. ECHO: display message on screen.
11. ENDLOCAL : End location of environment changes in a batch file.
12. EXIT: Quit the current script/ routine and set an error level.
13. FOR/F: Loop command/ against a set of files
14. FOR: loop command/ all option files, directory, list.
15. FTYPE: File extension.
16. GOTO: Direct a batch program to jump to a labelled line.
17. IF: Conditionally perform a command
18. MD: create new folder
19. MKLINK: create a symbolic link
20. MOVE: Move file
21. PATH: Display or set a search path of executable files
22. PAUSE: suspend processing of a batch file and display a message
23. POPD: Return to a previous directory saved by PUSHD
24. PROMPT: Change the command PROMPT
25. PUSHD: Save and then change the current directory
26. REM: Record comment (Remarks) in a batch file
27. REN: Rename a file or folder
28. RD: Delete folder
29. SET: Display, set, or remove session environment variables
30. SETLOGAL: Control the visibility of environment variables
31. SHIFT: Shift the position of batch file parameters.
32. TIME: Display or set the system time
33. TITLE: Set the windows title for a CMD.EXE session
34. TYPE: Display the contents of text file
35. VER: Display version information.
36. VERIFY: Verify that files have been saved
37. VOL: Display a disk label
38. :: - comment remarks

2. External command: 

➧ Reside on external memory (hard disk)

➧ All executable files with extensions .com, .exe and .bat are the external command.

List of External command:

1. Append
2. Assign
3. Attrib
4. Backup
5. Bootsect
6. Cacls
7. Chkdsk
8. Choice
9. Comp
10. Compact
11. Convert
12. Debug
13. Defrag
14. Deltree
15. Diskcomp
16. Diskcopy
17. Doskey
18. Dosshell
19. Edit
20. Expand
21. Extract
22. Fasthelp
23. Fc
24. Fdisk
25. Find
26. Format
27. FTP
28. Help
29. Ipconfig
30. Label
31. Mem
32. Mode
33. More
34. Msav
35. msbackup
36. ping
37. power
38. print
39. shutdown
40. sort
41. subst
42. scandisk
43. sys
44. tree
45. undelete
46. unformat
47. xcopy

FUNCTION OF COMMAND:

1. CLS: Clear the screen.

    C:\>cls

2. DATE: to set or display the system date.

    c:\ date

3. TIME: To set or display set or time.

    C:\ time

4. DIR: To list content of disk.

5. dir/p: p is switch. which does the other operation. it display screen file.

6. dir/w: To display content in wide pattern without file detail [] separate the directory.

7. dir/b: List without details and without formatting (bare format) in this command we can't separate file and directory.

8. dir/s: To list content or disk including sub directory

9. dir/o: sorting the list of directory.

10. dir/o:n sorting with descending order

    ❤ Attribute:

    ❤ h=hidden

    ❤ r= rad only

    ❤ s= system

    ❤ d= directory

11. dir/ah: show the hidden file and folder

12. dir/ad: to list directory only

13. dir/?: display the all swithc with dir command

14. help: provide help about any command

15. copy con: to create the text file

16. type: to list content of file

17. ren/rename: to give new name ofr file/folder.

18. scandisk: to fix the disk error to solve minor disk problem

19. mem: to display space of internal memory.

20. Label: To set the label (name and disk)

21. vol: to display volume lable and series of disk

22. ver: to display version of  OS

23. find: to search specific string/ sord into a text file.

24. sort: sorting the content file

25. sys: to transfer the system file from one disk to another disk.

26. tree: to display directory structure and disk ifle.

27. xcopy: to copy file including sub directory except hidden file.

28. diskcomp: to compare to disk

29. diskcopy: it transfer the entire content of one disk to another.

30. fdisk: to create partion on large disk

31. restore: it retrive back the file from compressed file (backup)

32. backup: it copy the file from regular storage to remove ablae storage by compressing file.

33. restore: it retrieve file and data from backup file.

34. defrag: it is used to reduce the number of file which are fragment.

35. break: it break the continues operation

36. DOS key: to record every kestroke/press key and command.

37. F7: to display list of command which are already used.

38. Exit: to return back to windows OS or Exit/goes to windows from dos

39. Edit: to create, modify, a text file

40. recover: it is used to recover the data/file from disk.