SWIG

From Wikipedia, the free encyclopedia

SWIG (Simplified Wrapper and Interface Generator) is an open source software tool used to connect programs or libraries written in C/C++ with scripting languages such as Tcl, Perl, Python, Ruby, PHP and other languages like Java, C#, Scheme and Ocaml.

The aim is to achieve this connection with minimal effort: a small number of directives are added to the program's header files, and then the SWIG tool creates source code which provides the glue between C/C++ and the target language. Depending on the language, this glue comes in three forms:

an executable that behaves like the original program but embeds an interpreter for the scripting language,
a shared library that an existing interpreter can link to as some form of extension module, or
a shared library that can be linked to other programs compiled in the target language (for example, using JNI in Java).

There are two main purposes of embedding a scripting engine into an existing C/C++ program:

The program can then be customized much more quickly, using the scripting language rather than C/C++. The scripting engine may even be exposed to the end user, so that they can automate common tasks by writing scripts.
Even if the final product is not to contain the scripting engine, it may nevertheless be quite useful to write testing scripts.

There are several reasons to create dynamic libraries that can be loaded into existing interpreters, including:

Provide access to a C/C++ library which has no equivalent in the scripting language.
Write the whole program in the scripting language first, and after profiling, rewrite performance critical code in C or C++.

SWIG is written in C and C++ and has been publicly available since February 1996. The initial author and main developer was Dave Beazley, now at the University of Chicago, who developed SWIG while working as a graduate student at Los Alamos National Laboratory and the University of Utah. Development is currently supported by an active group of volunteers. SWIG has been released under a BSD type license, meaning it can be used, copied, modified and redistributed freely, for commercial and non-commercial purposes.