abf

abf is a Brainfuck interpreter written in x86-64 Assembly for Linux.

Usage

Usage: abf [OPTION] FILE
abf is a brainfuck interpreter written in Assembly.

Options:
    -s, --tape-size=NUM    The tape size to use (default: 5000)
                           Change this if your program overflows the default tape size
    -v, --verbose          Show timing information

The FILE argument must point to a file containing a brainfuck program.

Examples:

  Execute a program from stdin:
    $ echo "+++++++++++++++++++++++++++++++++.-----------------------." | abf -

  Execute a program from a file:
    $ abf hello_world.bf

  Execute a program from a file with tape size 10000:
    $ abf -s 10000 large_tape.bf

Installation

Installation should be pretty easy on a normal x86-64 Linux system.

1. Clone the repository

   git clone https://github.com/xarantolus/asm-bf

2. Change to its directory

   cd asm-bf

3. Install to /usr/bin/abf

   sudo make install

4. Test if the installation worked by running an example program

   echo "+++++++++++++++++++++++++++++++++.-----------------------." | abf -

   This should output ! and a new line.

Interesting programs

Here are some interesting programs you can run with this interpreter.

Program name	Description	Command	Source
Hello World	The typical "Hello World!" program	curl "https://gist.githubusercontent.com/kidk/44b8cd699c5879f1084f/raw/e7ae1b5be4b5a9f117b2948e5391b6d464327996/hello-world.b" | abf -	Source
Towers of Hanoi	Towers of Hanoi visualization	curl "https://web.archive.org/web/20200130201116if_/http://www.clifford.at:80/bfcpu/hanoi.bf" | abf -	Source (Web Archive)
Mandelbrot	Mandelbrot visualization	curl "https://raw.githubusercontent.com/erikdubbelboer/brainfuck-jit/master/mandelbrot.bf" | abf -	Source
e	Computes the transcendental number e	curl "http://www.brainfuck.org/e.b" | abf -s 100000 -	Source
Fibonacci Sequence	Outputs the fibonacci sequence	curl "http://www.brainfuck.org/fib.b" | abf -	Source

You can find more interesting programs on brainfuck.org.

And if you want to do something even more interesting, you can just execute 5MB of random (printable) bytes:

cat /dev/urandom | tr -cd "[:print:]\n" | head -c $((5<<20)) | abf -v -

Code overview

The interpreter source code can be found in bf/bf.S. It directly executes system calls from Assembly and thus does not depend on any libraries to read from stdin/write to stdout. Since output is not buffered and each byte is written individually, writing should be rather slow.

The rest of the program (handling command-line arguments, reading input files etc.) is written in C.

Memory Safety

The interpreter does bounds checks to avoid over/underrunning the program string and machine tape (it will show an error message when that happens and terminate safely).

License

This is free as in freedom software. Do whatever you like with it.