C Befunge Interpreter

This Befunge interpreter has full support for Befunge-93.

Extra Non-93 Features:

• Support for an instruction space of arbitrary size

• Allows pushing hex digits (0-f) as integers

• Allows turning the instruction pointer relative to the current direction

• Allows repeating commands

• Continuous skipping

• Skipping n cells

Supported Commands

Command	Description
0...f	push numerical value
+	pop a, b and push a + b
-	pop a, b and push b - a
*	pop a, b and push a * b
/	pop a, b and push b / a (integer division)
%	pop a, b and push b % a (modulus on integers)
!	pop a, if a is 0 push 1, else push 0 (logical not)
`	pop a, b and push b > a
'	push the next cell as an ascii
"	start string mode, push next cells as ascii up to the next "
.	pop numerical value from stack and print
,	pop ascii value from stack and print
:	duplicate the top of the stack
\	swap the top two values on the stack
$	discard the top value on the stack
k	pop n, run next command n + 1 times
^	set instruction pointer delta to (0, 1)
v	set instruction pointer delta to (0, -1)
<	set instruction pointer delta to (-1, 0)
>	set instruction pointer delta to (1, 0)
[	turn the instruction pointer left relative to direction
]	turn the instruction pointer right relative to direction
r	reverses the instruction pointer delta
?	sets the instruction pointer to a random dirction
_	horizontal if, pop a, if a = 0, move right, else move left
|	vertical if, pop a, if a = 0, move down, else move up
#	jumps over the next cell
;	turns off execution until next ;
j	pop n, jump over the n next cells
&	get an integer from the user and push it
~	get a character from the user and push it
g	pop y, x and push the character in the position (x, y), else push 0
p	pop y, x, a and push the ascii value a into the position (x, y)
@	halt

Usage

cbi <befunge source>

To Compile

To compile "as is" requies gcc. Windows users can use MinGW (tested) or possibly Cygwin (untested). If you use a different compiler than gcc, you can either tweak the makefile or just compile directly from the command line.

Windows (MinGW32 example, may be slightly different)

cd src
mingw32-make win

Linux

cd src
make linux

Example Programs

Source File	Description
calc.bf	A REPL for Befunge math operators
hw.bf	Hello World

TODO

Add more example programs. Feel free to submit your own and I will merge them in after testing to make sure they work.