cmd.exe

Command Prompt (cmd.exe)

Other names	Windows Command Processor
Developer(s)	Microsoft, IBM, ReactOS contributors
Initial release	December 1987; 36 years ago (1987-12)
Operating system	Windows NT family Windows CE family OS/2 eComStation ArcaOS ReactOS
Command-line interpreter

Command Prompt, also known as cmd.exe or cmd, is the default

Multiple commands can be processed in a single command line using the command separator &&.[8]

When using this separator in the Windows cmd.exe, each command must complete successfully for the following commands to execute. For example:

C:\>CommandA && CommandB && CommandC

In the above example, CommandB will only execute if CommandA completes successfully, and the execution of CommandC depends on the successful completion of CommandB. To process subsequent commands even if the previous command produces an error, the command separator & should be used.^[9] For example:

C:\>CommandA & CommandB & CommandC

On Windows XP or later, the maximum length of the string that can be used at the command prompt is 8191 (2¹³-1) characters. On earlier versions, such as Windows 2000 or Windows NT 4.0, the maximum length of the string is 2047 (2¹¹-1) characters. This limit includes the command line, individual environment variables that are inherited by other processes, and all environment variable expansions.^[10]

Quotation marks are required for the following

& < > [ ] { } ^ = ; ! ' + , ` ~

The following is a list of the Microsoft OS/2 internal cmd.exe commands:^[11]

Windows NT family

The following list of internal commands is supported by cmd.exe on Windows NT and later:^[12]

Windows CE

The following list of commands is supported by cmd.exe on Windows CE .NET 4.2,^[13] Windows CE 5.0^[14] and Windows Embedded CE 6.0:^[15]

In addition, the net command is available as an external command stored in \Windows\net.exe.

ReactOS

The ReactOS implementation includes the following internal commands:^[2]

Comparison with COMMAND.COM

On Windows, cmd.exe is mostly compatible with COMMAND.COM but provides the following extensions over it:

• More detailed error messages than the blanket "Bad command or file name" (in the case of malformed commands) of COMMAND.COM. In OS/2, errors are reported in the chosen language of the system, their text being taken from the system message files. The HELP command can then be issued with the error message number to obtain further information.
• Supports using of arrow keys to scroll through command history. (Under DOS this function was only available under
  HISTORY) and later via an external component called DOSKEY
  .)
• Adds rotating command-line completion for file and folder paths, where the user can cycle through results for the prefix using the Tab ↹, and ⇧ Shift+Tab ↹ for reverse direction.
• Treats the caret character (^) as the escape character; the character following it is to be taken literally. There are special characters in cmd.exe and COMMAND.COM (e.g. "<", ">" and "|") that are meant to alter the behavior of the command line processor. The caret character forces the command line processor to interpret them literally.
• Supports delayed variable expansion with SETLOCAL EnableDelayedExpansion, allowing values of variables to be calculated at runtime instead of during parsing of script before execution (Windows 2000 and later), fixing DOS idioms that made using
  control structures hard and complex.^[16]
  The extensions can be disabled, providing a stricter compatibility mode.

• The
  switch
  .
• SetLocal and EndLocal commands limit the scope of changes to the environment. Changes made to the command line environment after SetLocal commands are local to the batch file. EndLocal command restores the previous settings.^[17]
• The Call command allows subroutines within batch file. The Call command in COMMAND.COM only supports calling external batch files.
• File name parser extensions to the Set command are comparable with C shell.^{[further explanation needed]}
• The Set command can perform
  expression evaluation
  .
• An expansion of the For command supports parsing files and arbitrary sets in addition to file names.
• The new
  PopD commands provide access past navigated paths similar to "forward" and "back" buttons in a web browser or File Explorer
  .
• The conditional IF command can perform
  PC DOS or MS-DOS
  .)

• Comparison of command shells
• List of DOS commands
• COMMAND.COM
• PowerShell
• Windows Terminal

References

Further reading

• David Moskowitz; David Kerr (1994). OS/2 2.11 Unleashed (2nd ed.).
  ISBN 978-0672304453
  .
• Stanek, William R. (2008). Windows Command-Line Administrator's Pocket Consultant (2nd ed.).
  ISBN 978-0735622623
  .

External links

Wikimedia Commons has media related to Windows Command Prompt.

Wikibooks has a book on the topic of: Windows Batch Scripting

• "Command-line reference A-Z". Microsoft. April 26, 2023.
• "Cmd". Microsoft Windows XP Product Documentation. Microsoft. Archived from the original on September 2, 2011. Retrieved May 24, 2006.
• "Command Prompt: frequently asked questions". windows Help. Microsoft. Archived from the original on April 22, 2015. Retrieved April 20, 2015.
• "An A–Z Index of the Windows CMD command line". SS64.com.
• "Windows CMD.com – Hub of Windows Commands". windowscmd.com. Archived from the original on January 11, 2022. Retrieved January 4, 2022.