Example of internal and external dos command?

Answer 1

Most Commonly Used Internal DOS Commands1. DATE

This command is used to display the system current date setting and prompt you to enter a new date. The syntax is: DATE [/T | date]

2. TIME

This command is used to displays or set the system time.

The syntax is: TIME [/T | time]

3. COPY CON

It is used to create a file in the existing directory. Syntax is: COPY CON filename after that press Enter and start typing your text and after you're done typing your text, to save and exit hit F6 key.

4. TYPE

This command is used to display the contents of a text file or files. The syntax is: TYPE [drive:][path]filename

Now, lets try to display the contents of the file named filename we've created earlier using COPY CON command.

5. REN

This command is used to change/modify the name of a file or files.

Syntax is: REN [drive:] [path] filename1 filename2.

6. DIR

This command displays a list of files and subdirectories in a directory. Syntax is: DIR [drive:] [path] [filename] [/A[[:]attributes]] [/B] [/C] [/D] [/L] [/N] [/O[[:]sortorder]] [/P] [/Q] [/S] [/T[[:]timefield]] [/W] [/X] [/4]

/A:attributes

Delete files based on specified attribute. The attributes are: R for Read-only files, S for System files, H for Hidden files, A for files ready for archiving and - Prefix meaning not.

7. COPY

This command is useful in copying one or more files to another file or location. Syntax is COPY [/D] [/V] [/N] [/Y | /-Y] [/Z] [/A | /B ] source [/A | /B] [+ source [/A | /B] [+ ...]] [destination [/A | /B]]

8. MD, CD and RD

o MD (or MKDIR) command stand for make directory and it is used to create a directory.

Syntax is MD [drive:]path

CD (or CHDIR) stands for create or change directory and it allows to display the name of or change the current directory or rather we can say come out of a directory. Syntax is CD [/D] [drive:][path]

9. RD (or RMDIR) command removes or deletes a directory. There are two conditions to remove any directory - (1) Directory to be removed should be empty. and (2) We should be outside the directory we are commanding to delete.

Syntax is RD [/S] [/Q] [drive:]path

10. CLS

It is used to clear the screen. Syntax is CLS

Most Commonly Used External DOS Commands1. EDIT

This command is used to modify or change the data of a file.

Syntax is EDIT [/B] [/H] [/R] [/S] [filename(s)]

Using switch /B you can force the edit in monochrome mode. /H displays the maximum number of lines possible for your system hardware. Whereas using /R and /S one can load files in read-only mode and force the use of short filenames respectively. [filename(s)] is used to specify file(s) to go edit. You can use wildcards (* and ?) to specify multiple files.

2. XCOPY

This command is used to copy files and directory trees from one disk to another disk.

Syntax is XCOPY source [destination] [/A | /M] [/D[:date]] [/P] [/S [/E]] [/V] [/W] [/C] [/I] [/Q] [/F] [/L] [/G] [/H] [/R] [/T] [/U] [/K] [/N] [/O] [/X] [/Y] [/-Y] [/Z] [/EXCLUDE:file1[+file2][+file3]...]

3. LABEL

It is used to create, change, or delete the volume label of a disk.

Syntax is LABEL [drive:] [label]

LABEL [/MP] [volume] [label]

Here, [drive:] is for secifying the drive letter of a drive to be labelled and [label] specifies the label of the volume disk. [/MP] is used to specify that the volume should be created as a mount point and [volume] is used to specify volume name, usually mentioned after drive letter followed by colon and then giving volume name required.

4. CHKDSK

This command is used to check a disk and display a status report with properties of disk like serial number, volume label, memory and other properties along with errors on the disk if any.

Syntax is CHKDSK [volume path] [/F] [/V] [/R] [/X] [/I] [/C] [/L[:size]]

5. FIND

This command searches for a specific text string in a file or files. Syntax is FIND [/V] [/C] [/N] [/I] [/OFF] "string" [[drive:][path]filename[ ...]]

The basic essential elements in the command line for find are - the string enclosed in " " and [[drive:][path]filename(s)]. String specifies the text string to find in the file and [[drive:][path]filename(s)] specifies the file or files where the text string search is to be done. If a path is not specified, FIND searches the text typed at the prompt or piped from another command. When you append /OFF in the command line, it searches and finds even those files with offline attribute set. Apart from searching the text string, this command is useful in:

• Displaying all lines not containing the specified string @ /V
• Displaying only the number count of lines containing the text string @ /C
• Displaying line numbers with the displayed lines @ /N

6. SORT

This command is used to arrange the data of a file in alphabetical order (A-Z, 0-9) or reverse alphabetical order.

Syntax is SORT [/R] [[drive1:][path1]filename1] [/T [drive2:][path2]] [/O [drive3:][path3]filename3]

/R in command line reverses the sort order; that is, the data of the specified file sorts sorts Z to A, then 9 to 0. [drive1:][path1]filename1 specifies the file to be sorted. /T [drive2:][path2] is used in cases of data overflow in main memory and it specifies the path of the directory to hold the sort's working storage. And /O [drive3:][path3]filename3 specifies the file where the sorted input is to be stored.

------Yours Rajinijana....

Answer 2

In MS-DOS there are two ways commands are executed. An Internal command, which is a command embedded into the command.com file, and an external command, which is not embedded into command.com and therefore requires a separate file to be used.

For example, if your computer does not have the fdisk.exe file and you try using the fdisk command, you would receive an error "Bad command or file name" error message. Fdisk is an external command that will only work if fdisk.exe, or in some cases, fdisk.com, is present.