This is a simple Brainf*ck interpreter in C which can detect and locate runtime errors.

Brainf*ck is a programming language created in 1993 by Urban Müller. It utilises a simple machine model, which consists of:

• A one-dimentional array of 30000 byte cells initialised to 0;
• A data pointer which points to the first element at the beginning of program execution;
• A program;
• An instruction pointer;
• An input stream (stdin);
• An output stream (stdout).

The eight single-character commands of the language are listed below. All the other characters are ignored. The commands in the program are executed sequentially unless a [ or ] command is encountered.

See Wikipedia for a more detailed explanation.

Building the interpreter requires make, clang, and git. To satisfy these requirements, you may need to install them using your package manager first. For instance:

$ sudo apt install build-essential clang git  # for Debian, Ubuntu, and related
$ sudo dnf install make clang git             # for Fedora, Red Hat, and related

Then the interpreter can be built with GNU Make:

$ git clone https://github.com/ZhongRuoyu/Brainfuck.git
$ cd Brainfuck
$ make

The last make command generates an executable named bf in the directory.

On platforms like Windows where make is not well supported, the interpreter can still be built manually. To do so, git clone this repository or download a zipped archive. Open a terminal in its root directory and build the executable using all the source files in /src, with include path /include. For instance, using clang on Windows with PowerShell:

clang src/*.c -I include -std=c11 -O2 -o bf.exe

To use the interpreter, simply supply the path to the Brainf*ck program as an argument. For instance, running the following...

$ bf test/hello.b

... executes the program at test/hello.b, and generates the following output:

Hello World!

The interpreter has the capability to detect and locate runtime errors. For instance, interpreting the following program...

        (pointer initially at location 0)
+++++   increment the value at cell 0 to 5
<       try decrementing the pointer
>       increment the pointer
[-]     reset the cell to 0

... generates the following error:

At Line 3, Column 1: error: decrementing pointer to inaccessible cell.
    <       try decrementing the pointer
    ^

Run bf --help to view the detailed help message on using the interpreter.

To execute the interpreter, you may need to key in its path as well.

A code golf version of the interpreter, based on commit a25de5a, is available here in ZhongRuoyu/CodeGolf.

Copyright (c) 2021 Zhong Ruoyu.

Unless otherwise stated, the files in this repository are licensed under the MIT License.