COMMAND.COM

Quality 0.50 · 3 views · Updated 2 months ago

Default command line for MS-DOS and Windows 9x

title: "COMMAND.COM" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["command-shells", "dos-command-shells", "windows-command-shells", "scripting-languages", "dos-files", "windows-files", "external-dos-commands", "msx-dos"] description: "Default command line for MS-DOS and Windows 9x" topic_path: "technology/programming-languages" source: "https://en.wikipedia.org/wiki/COMMAND.COM" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Default command line for MS-DOS and Windows 9x ::

::data[format=table title="Infobox software"]

Field	Value
name
screenshot	Command.com Win10.png
caption	in Windows 10
other_names	MS-DOS Prompt,
Windows Command Interpreter
developer	Seattle Computer Products, IBM, Microsoft, The Software Link, Datalight, Novell, Caldera
released
replaced_by
programming language	x86 assembly language
operating_system
platform	16-bit x86
genre	Command-line interpreter
::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/8/83/Microsoft_Windows_95_Version_4.00.1111_command.com_MS-DOS_Prompt_492x259.png" caption="COMMAND.COM}} running in a [[Windows console]] on [[Windows 95]] (MS-DOS Prompt)"] ::

**** is the default command-line interpreter for MS-DOS, Windows 95, Windows 98 and Windows Me. In the case of DOS, it is the default user interface as well. It has an additional role as the usual first program run after boot (init process). As a shell, has two distinct modes of operation: interactive mode and batch mode. Internal commands are commands stored directly inside the binary; thus, they are always available, but can only be executed directly from the command interpreter.

Description

's successor on OS/2 and Windows NT systems is cmd.exe, although COMMAND.COM is available in virtual DOS machines on IA-32 versions of those operating systems as well. The filename was also used by (DCP), an MS-DOS derivative by the former East German VEB Robotron.

is a DOS program. Programs launched from are DOS programs that use the DOS API to communicate with the disk operating system. The compatible command processor under FreeDOS is sometimes also called FreeCom.

Operating modes

As a shell, has two distinct modes of operation. The first is interactive mode, in which the user types commands which are then executed immediately. The second is batch mode, which executes a predefined sequence of commands stored as a text file with the .BAT extension.

{{anchor|Prompt}}Internal commands

Internal commands are commands stored directly inside the binary. Thus, they are always available but can only be executed directly from the command interpreter.

All commands are executed after the key is pressed at the end of the line. is not case-sensitive, meaning commands can be typed in any mixture of upper and lower case.

; : Controls the handling of program interruption with or . ; : Displays or changes the current system code page. ; , : Changes the current working directory or displays the current directory. ; : Clears the screen. ; : Copies one file to another (if the destination file already exists, MS-DOS asks whether to replace it). (See also XCOPY, an external command that could also copy directory trees). ; : Defines the device to use for input and output. ; : Display and set the date of the system. ; , : Deletes a file. When used on a directory, deletes all files inside the directory only. In comparison, the external command deletes all subdirectories and files inside a directory as well as the directory itself. ; : Lists the files in the specified directory. ; : Toggles whether the commands executed by a batch file are displayed on screen () or not (). Also displays text on the screen (). ; : Exits from and returns to the program which launched it. ; : Enables or disables the return of long filenames by the command. (Windows 9x). ; , : Loads a program into upper memory ( in DR DOS). ; : Enables external programs to perform low-level disk access to a volume. (MS-DOS 7.1 and Windows 9x only) ; , : Creates a new directory. ; : Displays or changes the value of the environment variable which controls the places where will search for executable files. ; : Displays or change the value of the environment variable which controls the appearance of the prompt. ; , : Renames a file or directory. ; , : Removes an empty directory. ; : Sets the value of an environment variable; without arguments, shows all defined environment variables. ; : Display and set the time of the system. ; : Display the fully expanded physical name of a file, resolving , and SUBST logical filesystem mappings. ; : Display the content of a file on the console. ; : Disables low-level disk access. (MS-DOS 7.1 and Windows 9x only) ; : Displays the version of the operating system. ; : Enable or disable verification of writing for files. ; : Shows information about a volume.

Batch file commands

Control structures are mostly used inside batch files, although they can also be used interactively.

; label: Defines a target for . ; : Executes another batch file and returns to the old one and continues. ; : Iteration: repeats a command for each out of a specified set of files. ; : Moves execution to a specified label. Labels are specified at the beginning of a line, with a colon (). ; : Conditional statement, allows branching of the program execution. ; : Halts execution of the program and displays a message asking the user to press any key to continue. ; : comment: any text following this command is ignored. ; : Replaces each of the replacement parameters with the subsequent one (e.g. with , with , etc.).

IF command

On exit, all external commands submit a return code (a value between and ) to the calling program. Most programs have a certain convention for their return codes (for instance, 0 for a successful execution).

If a program was invoked by , the internal IF command with its conditional can be used to test on error conditions of the last invoked external program.

Under , internal commands do not establish a new value.

Variables

Batch files for can have four kinds of variables:

Environment variables: These have the form and are associated with values with the SET statement. Before DOS 3 will only expand environment variables in batch mode; that is, not interactively at the command prompt.
Replacement parameters: These have the form , ..., and initially contain the command name and the first nine command-line parameters passed to the script (e.g., if the invoking command was , then is , is and is ). The parameters to the right of the ninth can be mapped into range by using the SHIFT statement.
Loop variables: Used in loops, they have the format when run in batch files. These variables are defined solely within a specific FOR statement, and iterate over a certain set of values defined in that FOR statement.
Under Novell DOS 7, OpenDOS 7.01, DR-DOS 7.02 and higher, also supports a number of system information variables, a feature earlier found in 4DOS 3.00 and higher as well as in Multiuser DOS, although most of the supported variable names differ.

Redirection, piping, and chaining

Because DOS is a single-tasking operating system, piping is achieved by running commands sequentially, redirecting to and from a temporary file. makes no provision for redirecting the standard error channel.

; *command* ; command filename: Redirect [standard output](standard-streams-standard-output-stdout), overwriting target file if it exists. ;command filename: Redirect [standard output](standard-streams-standard-output-stdout), appending to target file if it exists. ;command1 | command2: Pipe [standard output](standard-streams-standard-output-stdout) from *command1* to [standard input](standard-streams-standard-input-stdin) of *command2* ;command1 ¶ command2` : : Commands separated by ASCII-20 (¶, invoked by ) are executed in sequence (chaining of commands). In other words, first command1 is executed until termination, then command2. This is an undocumented feature in of MS-DOS/PC DOS 5.0 and higher. It is also supported by of the Windows NT family as well as by DR-DOS 7.07. All versions of DR-DOS already supported a similar internal function utilizing an exclamation mark (!) instead (a feature originally derived from Concurrent DOS and Multiuser DOS) - in the single-user line this feature was only available internally (in built-in startup scripts like "!DATE!TIME") and indirectly through DOSKEY's $T parameter to avoid problems with ! as a valid filename character. 4DOS supports a configurable command line separator (4DOS.INI CommandSep= or SETDOS /C), which defaults to ^. in newer versions of Windows NT also supports an separator for compatibility with the cmd syntax in OS/2 and the Windows NT family. (cmd does not support the ¶ separator.)

Limitations

Generally, the command line length in interactive mode is limited to 126 characters. In MS-DOS 6.22, the command line length in interactive mode is limited to 127 characters.

In popular culture

The message "Loading " can be seen on a HUD view of the Terminator and the internal viewport of RoboCop when he reboots.
In the animated children's TV series ReBoot, which takes place inside computers, the leader of a system (the equivalent of a city) is called the .

References

Murphy, Kathleen. (July–August 1995). "Cyberscreens". [[Film Comment]] via Inwap.com.
"MS-DOS/COMMAND.ASM at master · microsoft/MS-DOS".
(1997-05-01). "BATTIPs — Tips & Tricks zur Programmierung von Batchjobs". MPDOSTIP.
(2003). "Exitcodes (errorlevels) of DOS utilities".
"Windows 95/98/ME ERRORLEVELs".
(2015-12-24). "MS-DOS errorlevels".
(1998). "Caldera DR-DOS 7.02 User Guide". [[Caldera, Inc.]].
(1998). "Caldera DR-DOS 7.02 User Guide". [[Caldera, Inc.]].
(1997-07-01). "MSDOSTIPs — Tips für den Umgang mit MS-DOS 5.0-7". MPDOSTIP.
(2002-02-27}}). "4DOS 8.00 online help".
(1997-07-30). "NWDOS-TIPs — Tips & Tricks rund um Novell DOS 7, mit Blick auf undokumentierte Details, Bugs und Workarounds". MPDOSTIP.
(2016-11-29). "Betriebssystem DCP".
(1997-05-01). "Hinweise zu JPSofts 4DOS 5.5b/c, 5.51, 5.52a und NDOS". MPDOSTIP.
(1994). "Undocumented DOS: A programmer's guide to reserved MS-DOS functions and data structures - expanded to include MS-DOS 6, Novell DOS and Windows 3.1". [[Addison Wesley]].

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::