DOS Internal Commands

These DOS commands are called internal commands because their code is included in COMMAND.COM, the DOS and Windows 9x command processor. Since COMMAND.COM is loaded into primary memory when DOS or Windows 9x is booted, the internal commands are always in memory and can be executed any time without first being fetched from disk (secondary memory).

This is in contrast to the disk-bound external commands, which reside only in secondary memory until the moment they are needed. Then they are loaded into primary memory by the operating system, but only if the OS can find the program on disk.

The syntax for frequently used DOS internal commands follows.

TIME

Displays current time and allows it to be changed.
Syntax: TIME

DATE

Displays current date and allows it to be changed.
Syntax: DATE

CLS

Clears the screen.
Syntax: CLS

DIR

Shows directory information of a diskette: name, size, and the date and time stamp of files.
Syntax: DIR [d:][path]
Optional switches:
/p Display dir info and pauses display when the screen is full
/w Display names and extensions only in five columns

To display a file directory listing for D:\DATA\LETTER\ANNUAL from different current directories:
D:\DATA\LETTER\ANNUAL> DIR
D:\DATA> DIR LETTER\ANNUAL
C:\WINDOWS> DIR D:\DATA\LETTER\ANNUAL

COPY

Copies a file. Name of copy may be the same as original, or different. Syntax: COPY [d:][path][name.ext] [d:][path][name.ext]
Optional switches:
/v Verify, copies the file and compares it with the original
/b Binary file

To copy a file from D:\BATCH to the root of A: drive A:\> COPY D:\BATCH\CL.BAT (from A: drive)
D:\BATCH> COPY CL.BAT A:\ (from D:\BATCH) To copy a file from the root of C: to A: drive and change its name A:\> COPY C:\MSDOS.SYS MSDOSSYS.BAK (from A:)
C:\> COPY MSDOS.SYS A:\MSDOSSYS.BAK (from the root of C:) To copy all of the files from the root of A: to D:\CCV\ENGCOMP A:\> COPY *.* D:\CCV\ENGCOMP (from A:)
D:\CCV\ENGCOMP> COPY *.* A:\ (from D:\CCV\ENGCOMP)

TYPE

Displays the contents of a file.
Syntax: TYPE [d:][path][name.ext]

To display the contents of the file MY.LET to the screen
A:\> TYPE MY.LET

DEL

Deletes a file from disk.
Syntax: DEL [d:][path][name.ext]

To delete one file: A:\> DEL A:\MY.LET To del all files in current directory A:\> DEL *.*

REN

Renames a file.
Syntax: REN [d:][path][name.ext] [d:][path][newname.ext]

To change the name of the file D:\LET\ANNUAL\99.DOC to 1999.DOC D:\LET> REN ANNUAL\99.DOC 1999.DOC (from D:\LET)
D:\DATA> REN \LET\ANNUAL\99.DOC 1999.DOC (from D:\DATA)
C:\WINDOWS> REN D:\LET\ANNUAL\99.DOC 1999.DOC (from C:\WINDOWS)

MD

Makes (creates) a new directory.
Syntax: MD [d:][path][dirname]

To create a directory named HERMIT in the root of D: drive D:\> MD HERMIT (from D:\)
C:\> MD D:\HERMIT (from C:\)

RD

Removes an existing directory (directory must be empty).
Syntax: RD [d:][path][dirname]

To remove the HERMIT sub-directory: D:\> RD HERMIT (from D:\)
C:\> RD D:\HERMIT (from C:\)

CD

Changes the current directory.
Syntax: CD [path][dirname]

To make D:\HERMIT the current directory D:\> CD HERMIT (from D:\)
D:\DATA> CD \HERMIT (from D:\DATA)
D:\DATA\SOURCE> CD \HERMIT (from D:\DATA\SOURCE)
D:\DATA\SOURCE> CD .. (from D:\DATA\SOURCE)

PATH

The PATH command is used to help the command interpreter find external commands which are not in the current directory. The command interpreter looks into the DOS environment for "PATH=" and then searches the paths (each separated from the next by a semicolon) that follow.
Syntax: PATH=[path;path;...]

To set the DOS PATH: PATH=C:\DOS;C:\PCW;\C:\BIN To display the current path: PATH

SET PROMPT

Used to specify the appearance of the DOS prompt.
Syntax: SET PROMPT=[metastring] (from the command line)

PROMPT=[metastring] (in a batch file)



Metastrings are combinations of DOS PROMPT characters

DOS PROMPT Character	Resulting prompt
$b	|
$e	(EOF marker)
$h	destructive bk space erases >, so just blinking cursor
$n	default drive
$q	=
$v	DOS version no
$$	the $ sign
$d	system date
$g	>
$i	<
$p	full path description
$t	system time
$p$_	full path description, skips line (_ = CR and LF)

Examples (from command line)

To make the prompt display the current drive & current path followed by > SET PROMPT=$P$G To have the prompt display the current date, time, and drive on separate lines SET PROMPT= $D$_$T$_$N$G