MSYS is a lightweight shell environment that comes in two flavors: it can be loaded as a MSYS shell to compile projects that will run under MSYS; or it can be loaded as a MinGW shell to compile native Window programs.
The GNU build process involves certain tools, such as autoconf, which are hard to port to native Windows. But these tools are needed to build native Windows applications from sources packaged in a form to enable the GNU build process. MSYS allows running these tools. Applications that can run inside MSYS but not in Windows cmd.exe belong to a category of applications referred to as MSYS Applications.
The shell environment provides a hand picked set of tools to allow a typical configuration script with Bourne Shell syntax to execute. This allows most of the GNU packages to create a Makefile just from executing the typical configure script; this may then be processed by the GNU make utility, provided with MSYS, to build the package using the native MinGW version of GCC.
The POSIX layer used by MSYS is a fork of the 1.3.3 version of Cygwin. Cygwin is a full POSIX layer and UNIX-like environment for Win32 providing both server and client utilites. The MSYS adaptation of this has a much more modest objective: primarily to facilitate the mapping of POSIX style path names, as used in Makefiles and shell scripts, to suitable path names within the native Windows file system.
For more MSYS-specific information, please see the MSYS section of this website.
Programs included in MSYS
- If your PATH has duplicate entries in it, /etc/fstab may contain redundant or unnecessary entries.