Command.com

command.com is the name for MS-DOS's default shell (or command line interpreter). It also has an additional role, as the first program being ran after boot, hence being responsible for setting up the system as specified in the autoexec.bat and config.sys configuration files, and being the ancestor of all processes.

As a shell, command.com has two distinct modes of work. First is the interactive mode, in which the user types commands which are then executed in front of his eyes. The second is the batch mode, which executes a pre-defined sequence of commands written down at a text file, with the extension .bat. The original concepts for both functionalities is almost certainly derived from the Unix shells, although most programmers would find command.com less able than its counterparts. However, the batch file format allowed for built-in scripting inside MS-DOS, which was and still is a very useful feature.

Table of contents 1 Syntax 2 Filesystem commands 2.1 Other commands 2.2 Control structures 3 Variables 4 See also 5 External links

Syntax

Note that this section does not try to give a full overview to the syntax of command.com, but rather serve as an overview and a mnemonic for the most common and interesting features. Note that all commands are run only after the Enter key is pressed at the end of the line. command.com is case-insensitive, meaning commands can be typed in either case and are all equivalent (so dir, DIR and DiR will all work in the same way).

Filesystem commands

In accordance with command.com's main function as an operating system shell, it includes a number of built-in commands for working with files.

In order to run a program, simply type the name of its executable and then press "Enter" (it is not necessary to use the extension, e.g. nc.exe can be summoned simply as nc). In order to change the current working drive (see Drive letter assignment), type its letter followed by a colon (D:). Other filesystem commands include:

DIR

Lists the files in the current directory

CD, CHDIR

Changes the current working directory or displays the currect directory. CD is best since it is shorter.

COPY

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)

MOVE

The same as COPY, but removes the original afterwards. (MS-DOS 6 and higher).

DEL, ERASE, DELETE

Deletes a file. DEL is best since it is the shortest. (See also DELTREE[?], an external command which can delete entire directory trees)

MD, MKDIR

Create a new directory

RD, RMDIR

Removes an empty directory

Other commands