Dos Commands Interview Questions

MS-DOS is an operating system developed by Microsoft. It is a non-graphical command-line based operating system developed for x86-based computers. Released in the year of 1981, MS-DOS was originally written by Tim Paterson. Though not used by many today, MS-DOS was one of the popular operating systems throughout the 1980s. MS-DOS is a closed-source operating system that features a monolithic kernel.

The first Windows with GUI used M-DOS as the underlying basic operating system. This command-line based system was preferred for its flexibility and stability, but the rise of the GUI based operating system led to its inevitable downfall.

Some of the features of the MS-DOS are,

• MS-DOS is a command-line based operating system and it doesn’t support the graphical user interface. It requires text and codes to operate.
• It is a 16-bit operating system.
• MS-DOS doesn’t support multi-programming so you can only run one process at a time in the RAM.
• The file names in the MS-DOS are limited to eight characters, with the three-character suffix denoting the type of the file.

Microsoft Disk Operating System is the full form of MS-DOS.

MS-DOS was once popularly used in all personal computers before the arrival of the GUI based systems. As it is a command-line based system, it doesn’t use many resources and offers high stability. With MS-DOS, users are able to navigate, open, and manipulate files stored on their computer through the command line.

Some of the common MS-DOS commands are,

• Cd - it is used to change or navigate directories
• Cls - it is used to clear the screen
• Cmd - it opens the command interpreter
• Color - it is used to change the foreground and background color of the MS-DOS window
• Copy - it copies one or more files from one location to another
• Del - it is used to deleting one or more files
• Dir - it is used to list the contents of the directory
• Echo - it is used to display messages
• Fc - it is used to compare files
• Help - it is used to display the list and brief explanation of a command

MS-DOS was first released the year of 1981.

The two types of DOS commands are internal and external commands. The DOS commands whose specifications are internally available in the command.com file and can be easily accessed are called internal commands. These are the more commonly used command.

Some examples of internal commands are cls, dir, date, time, etc.

External commands are kept in a separate file from the internal command which helps to fix problems, improve performance, or perform other actions. They are powerful commands and have high resource requirements than internal commands.

Some examples of external commands are Attrib, Tree, More, Edit, Label, etc.

The XCOPY command is used to copy a folder or directory from one destination to another.

//syntax

XCOPY source [destination]

You have to list the source and destination to copy the source folder to the destination folder.

The DELTREE command is used to delete a directory including all the files and sub-directories in it. It deletes the files even if the file has aa hidden, system, read-only, or other attributes.

//syntax
DELTREE [/Y] [drive:]path

The /Y suppresses prompting to confirm you want to delete the subdirectory. The [drive:]path specifies the name of the directory that you want to delete.

The dir command is used to list the files and subdirectories in a directory. The "/O:D" with the dir command is used to list the files by the date of the modification from the oldest first.

//syntax
dir /O:D

There are many ways to open the command prompt shell in Windows 10.

Some of the most commonly used ones are,

• Press Windows+X and then click "Command Prompt".
• Press Windows+R and then enter "cmd", and click to open the command prompt.
• You can also search for the command prompt in the start menu search to open it. In the file explorer, click the address bar or press Alt+D. Then type "cmd" into the address bar and hit enter to open the command prompt from that directory.

The mkdir command is used to create a new directory in the current directory.

//syntax

mkdir directory_name

It creates a new directory with the name that you specified in the current directory that you are working on.

The CD (Change Directory) command is used to change the directory or navigate to another folder. The "CD\" command is used to takes you to the top of the directory tree. To go to a specific folder, type "CD folder_name". Sub-folders are separated by a backslash character.