Subsystem for UNIX-based Applications Overview

Applies To: Windows Server 2003 R2

Subsystem for UNIX-based Applications (SUA) is the next-generation of Microsoft’s POSIX subsystem, similar to the Interix subsystem that formerly shipped with Windows Services for UNIX 3.5 or previous POSIX subsystems that shipped with Windows 2000 and NT 4.0. Subsystem for UNIX-based Applications and its accompanying utilities provide you with an environment that resembles any other UNIX system. It also includes case-sensitive file names, job control, compilation tools, and the use of over 300 UNIX commands and utilities and shell scripts. Because the Subsystem for UNIX-based Applications is layered on top of the Windows kernel, it offers true UNIX functionality without any emulation.

Installing Subsystem for UNIX-based Applications

Subsystem for UNIX-based Applications is available with Windows Server 2003 Release 2 (R2). You can install SUA using the procedures provided in the topic Install an optional component by using Add/Remove Windows Components.

Computing Environments with Subsystem for UNIX-based Applications

A computer running SUA provides two different command-line environments: the UNIX environment and the Windows environment. Applications run on specific subsystems and in specific environments. When you load Subsystem for UNIX-based Applications, you are using a UNIX environment; when you run applications on the Windows subsystem, you are using a Windows environment.

For example, when you use the Korn shell or C shell available with the download package Utilities and Software Development Kit (SDK) for UNIX-based Applications, or any other application that was compiled to run on SUA, you are using a UNIX environment. Among other things, this environment features case-sensitive file names and path names that use the format /usr/examples. For more information about the commands and utilities that are available in the Subsystem for UNIX-based Applications, see the Help files that ship with the download package Utilities and Software Development Kit (SDK) for UNIX-based Applications. This download package is available from the Microsoft Web site.

When you use the command processor cmd.exe, you are using the Windows environment. This environment includes case-insensitive file names, and path names that include drive letters, as shown in the following example: C:\SUA\usr\examples. For more information about path names in the Subsystem for UNIX-based Applications and Windows, see the Help files that ship with the download package Utilities and Software Development Kit (SDK) for UNIX-based Applications.

Porting Applications by Using Subsystem for UNIX-based Applications

Subsystem for UNIX-based Applications provides both the tools and the application programming interface (API) libraries for porting applications to run on Windows-based computers. With the Software Development Kit (SDK), which provides a front end for Microsoft Visual C++, you can have a UNIX environment for development, but still have the benefits of the native compiler for Windows. For more information about path names in Subsystem for UNIX-based Applications and Windows, see the Help files that ship with the download package Utilities and Software Development Kit (SDK) for UNIX-based Applications.

See Also

Other Resources

Installing and Using Utilities and SDK for UNIX-based Applications