Scripting Languages - The Bare Shell Script Basic program launch and installation scripts are often written using 'sh' or 'bash'. The shell is rather limited, but for many cases it suffices. It is also available on any Linux and any Unix platform. 'sh' and 'bash' support function definitions, executing external programs, IO redirection, and some primitive signal handling (so you could disable Ctrl-C in the middle of an important transaction). It is also useful to write primitive shell scripts when you need to launch a specific application in a non-standard environment (e.g. with a different path for loading shared libraries, or some other environment variables setup).