What is the difference between internal and external commands in MS-DOS?

Answer 1

INTERNAL COMMANDS

1. These are those commands which are contained in command.com files of MS-DOS.
2. These are those functions that are built into the command interpreter.
3. There is no need of any external file in computer to read internal MS-DOS command.
4. These commands can be used as long as DOS is running on the system.
5. Internal commands do not vary from system to system.
6. These are ver, time, del, md, cd, copy con, cls, date, vol, ren, copy etc.

EXTERNAL COMMANDS

1. These are those commands which are not in-built in MS-DOS.
2. External commands are those which are not included in the interpreter.
3. There is a need of an internal file in the computer to read external MS-DOS command.
4. External command may vary from system to system. This means any two computers with same version of MS-DOS may have same internal commands, but may have different external commands.
5. These are tree, xcopy, diskcopy, more, print etc.

Answer 2

What is the difference between internal and external commands?

The terms "internal and external" commands bring the Dos operating system in mind!

While the terms are still used these days, I'll refer to the Dos O/S example to help you understand the concept and their difference.

The Dos operating system requires a few critical files in order to work correctly, one of these is the 'command.com' file, which is a basic part of the operating system.

The following is a list of MS-DOS version 5.0 internal and external commands. The internal commands reside in COMMAND.COM, which loads into memory when the computer system is started; these commands do not reside on disk. The external commands are files that do reside on disk and have an extension of .COM, .EXE, or .BAT. Both command types are executed from the MS-DOS prompt.

Internal Commands

BREAK

CALL

CHCP

CHDIR(CD)

CLS

COPY

CTTY

DATE

DEL(ERASE)

DIR

ECHO

EXIT

FOR

GOTO

IF

MKDIR(MD)

PATH

PAUSE

PROMPT

REM

RENAME(REN)

RMDIR(RD)

SET

SHIFT

TIME

TYPE

VER

VERIFY

VOL

External Commands

APPEND.EXE

ASSIGN.COM

ATTRIB.EXE

BACKUP.EXE

CHKDSK.EXE

COMMAND.COM

COMP.EXE

DEBUG.EXE

DISKCOMP.COM

DISKCOPY.COM

DOSKEY.COM

DOSSHELL.COM

EDIT.COM

EDLIN.EXE

EMM386.EXE

EXE2BIN.EXE

EXPAND.EXE

FASTOPEN.EXE

FC.EXE

FDISK.EXE

FORMAT.COM

GRAFTABLE.COM

GRAPHICS.COM

HELP.EXE

JOIN.EXE

KEYB.COM

LABEL.EXE

MEM.EXE

MIRROR.COM

MODE.COM

MORE.COM

NLSFUNC.EXE

PRINT.EXE

QBASIC.EXE

RECOVER.EXE

REPLACE.EXE

RESTORE.EXE

SETVER.EXE

SHARE.EXE

SORT.EXE

SUBST.EXE

SYS.COM

TREE.COM

UNDELETE.EXE

UNFORMAT.COM

XCOPY.EXE

Answer 3

In MS-DOS there are two types of commands. 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 fdisk.exe and you try using the fdisk command, you would receive an error "Bad command or file name." Fdisk is an external command that will only work if fdisk.exe, or in some cases, fdisk.com, is present.

However, as long as MS-DOS is running on your computer internal commands such as the CD command will always be available and does not require any other files to run.

Computer Hope's MS-DOS page lists what commands are external and what are internal on each of the command pages. In addition, you can see our dictionary internal command page and/or external command page for a complete listing of each of the internal and external commands available.

Answer 4

Built-in commands are also known as internal commands. Internal commands are built into the command interpreter. On Linux systems normally used command interpreter is BASH shell. There are various shells available on Unix and Linux. Hence the list of internal commands varies for each shell. echo and cdare the typical examples of built-in commands. Bash also provides one more internal command called type. The typecommand accepts a name of command as an argument and displays one line description of the command passed as argument. The typecommand also indicates whether the command is built in the shell or not.

For eg

$ type echo

echo is a shell builtin

$ type cd

cd is a shell builtin

$ type pwd

pwd is a shell builtin

$ type type

type is a shell builtin

$ type rmdir

rmdir is bin

As can be seen from the example cd, pwd, type, and echo are buitin commands and rmdir is a external command. External commands are not included as a part of command interpreter, they are a separate binary files kept in specific path. Command interpreter runs this binary program whenever needed.

Answer 5

Internal and external refer to the command's location in relation to the kernel. An internal command is one built into MS-DOS's kernel. Such commands include CD, DEL, and MOVE. These commands cannot be removed from the system, as they are built-in to MS-DOS. In contrast, external commands are programs bundled with MS-DOS, but are not specifically built into the kernel. Such commands can include EDIT, COPY, and QBASIC. These commands previously resided in C:\DOS (where C is the drive letter), but in most versions of Windows, they will be found in C:|Windows\System32\Command (a user should check their system for specifics).

Answer 6

An internal command is one that is built into the shell or command interpreter, rather than executed as a separate binary.

Answer 7

Dos Internal commands are the one which are loaded in the Command.com file. External commands require their exe or com file to be present for execution.