Cattle is a GObject-based library that allows one to inspect Brainfuck programs in various ways, and to easily embed a full-featured Brainfuck interpreter into any application.
Cattle is able to load and execute virtually any Brainfuck program; both the code loader and the interpreter have good error checking, and are able to catch common coding errors such as unbalanced brackets.
Interpreters support flexible I/O using callbacks, which means it is possible to load a program's input from any source and send its output to any source. Examples include loading the program's input from a GTK+ widget and sending its output to a network socket.
The behaviour of an interpreter can be further customized, for example by enabling or disabling the runtime debugging support.
While program execution is a very important aspect of Cattle, it is possible to process a loaded programs in many ways, including adding or removing instructions.
The library currently provides enough features to implement a working
interpreter in about 70 lines of code (see examples/run.c); the
API is stable and considered good enough for production use.
The main limitation of Cattle lies in its performances: while it performs better than many interpreters written in a high-level programming language and than most naive interpreters written in C, it is easily outperformed by any optimized interpreter written in C.
The reason is mainly the overhead imposed by the GObject type system; while it would certainly be possible to dump GObject, I feel the features it provides are worth the performance hit.
The project's website contains pointers to the canonical Git repository, which you should clone if you're interested in hacking on Cattle, and the official release archives, which you should use otherwise.
Several distributions provide packages for Cattle: if your distribution is among those, you should use your package manager to install Cattle instead of building from source.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.