Dos Commands

DOS Commands Commands are the way of communicating with computers. Anything we want the computer system to do is told in the form of commands in the predefined syntax. DOS has two types of commands: -

# Internal Commands # External Commands

Internal commands: These are those commands for which the code for executing them is stored in COMMAND.COM and they execute without the requirement of any other file. When an internal command is issue by the user, the transient portion knows what to do & executes that command.

External commands: These are the independent executable files that can be used as separate utilities also. Information about these files is also stored in the transient portion. When an external command is issued, the transient portion picks up the relevant file of that command & executes it.

INTERNAL COMMANDS 1

1. Date – It displays the current system date & prompts you to change the date, if necessary. Syntax: C:\>date <mm-dd-yy> 2. Time – It sets the computer’s internal clock if command is issued with parameters otherwise displays the system time. Syntax: C:\>time 3. Clear Screen – It clears the screen. The cleared screen shows only the command prompt & the blinking cursor. Syntax: C:\>cls 4.Ver – Ver command displays the MS-DOS version no. Syntax: C:\>ver 5. Vol: - It displays the current volume label and the serial number of the specified drive. If drive specifier is omitted Vol takes the current drive by default. Syntax: C:\vol (Internal Commands continued…………)

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6. Break – It enables the DOS to check for Ctrl + C & Ctrl – break as the signal to terminate the current program less frequently. If you run Break without any parameters, the current state of break checking is displayed. Syntax: C:\>break 7. MKDIR (or MD) – It creates a multilevel directory. Syntax: C:\>MKDIR (or MD) <path> 8. CHDIR (or CD) – It changes the current directory or displays the name of the current directory. Syntax: C:\>CHDIR (or CD) < path> 9. Dir – It displays the list of the files & sub-directories that are in the directory specified. Syntax: C:\> dir <path> 10. Copy – It copy one or more files to the location specified & can also be used to combine. Syntax: C:\>copy <source> (Internal Commands continued…………)

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11. EDLIN – It is the line-oriented text editor. Syntax: C:\>EDLIN 12. Del – It deletes the files specified. Syntax: C:\>del <path> 13. Prompt – It chanes the appearance of the command prompt or displays the current prompt. Syntax: C:\>prompt 14. RMDIR (or RD) – It removes the directory. Syntax: C:\>RMDIR (or RD) <path> 15. Rename (or REN) – It changes the name of the file or files specified & can also rename all files matching the specified filename. Syntax: C:\>rename (or REN) <path>

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16.Type – It displays the contents of a text file or view the contents of any text file without modifying it. Syntax: C:\>type <path> 17. Path – It is used to earch for the executable files in the directories specified. Syntax: C:\> path <path> <……> 18. Verify – It verifies that the files are written correctly to the disk. Syntax: C:\>verify

Externel Commands

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1. Attrib – It lets you display or alter the attributes assigned to a file or directory. Syntax: C:\>attrib <+A/-A><+H/-H><+R/-R><+S/-S> <path> +A: - add archive attributes -A: - remove archive attribute +H : - add hidden attributes -H: - remove hidden attribute +R: - add read-only attributes -R: - remove read-only attribute +S: - add system attributes -S: - remove system attribute 2. Chkdsk – It checks a disk’s file allocation table entries for errors & find whether the files are o.k. or not. Syntax: C:\>chkdsk <path>

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3. Comp – It compares two files byte-by-byte and reports the differences. Syntax: C:\>comp [<path+filename>] [<path+filename>] 4. Format – It creates a new directory & file allocation table for the disk. Syntax: C:\>format 5. Scandisk – It checks a drive for errors and corrects any problems that it finds. Syntax: C:\> scandisk 6. Tree – The structure of the specified drive from the specified directory down, listing all the sub-directories it encounters is displayed graphically. Syntax: C:\>tree

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7. Deltree – It deletes a directory and all the files and subdirectories contained within it. Syntax: C:\>deltree <path> 8. XCopy – It is used to copy all the files in a directory, including the files in the sub-directories of that directory. Syntax: C:\>xcopy <source> <destination> 9. Print – It prints a text file. Syntax: C:\>print 10. FDisk – It is the tool, DOS provides for setting up and managing hard disk partitions. Syntax: C:\>fdisk 11. Label – It lets you create, modify or delete the label assigned to a disk. Syntax: C:\>label (External Commands continued…………)

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12.Doskey – It edits command lines, recalls command lines and creates macros. Syntax: C:\>doskey 13.More – It displays one screen of output at a time and in end of each screen displays the message. Syntax: C:\>more <path> 14. Backup – It lets the user to take the backup of hard disk files to floppies. Syntax: C:\>backup <source> <destination> 15.Restore – It restores the files that were backed up on a floppy. Syntax: C:\>restore <path> 16. Mem – It displays amount of used and free memory in the system. Syntax: C:\>mem (External Commands continued…………)

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17. FC – It compares two files or sets of files and displays the difference between them. Syntax: C:\>fc

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