DZone Snippets: bf code

bell.bf

mcandre (Andrew Pennebaker) — Mon, 19 Feb 2007 00:57:08 GMT

// Sounds the system bell



URL: http://snippets.dzone.com/posts/show/3539



add seven

while not zero

	putchar

	minus one



+++++++[.-]

rot13.bf

mcandre (Andrew Pennebaker) — Mon, 19 Feb 2007 00:55:19 GMT

// ROT13 in Brainfuck



URL: http://snippets.dzone.com/posts/show/3538



+[,+[-[>+>+<<-]>[<+>-]+>>++++++++[<-------->-]<-[<[-]>>>+[<+<+>>-]<[>+<-]<[<++>

>>+[<+<->>-]<[>+<-]]>[<]<]>>[-]<<<[[-]<[>>+>+<<<-]>>[<<+>>-]>>++++++++[<-------

->-]<->>++++[<++++++++>-]<-<[>>>+<<[>+>[-]<<-]>[<+>-]>[<<<<<+>>>>++++[<++++++++

>-]>-]<<-<-]>[<<<<[-]>>>>[<<<<->>>>-]]<<++++[<<++++++++>>-]<<-[>>+>+<<<-]>>[<<+

>>-]+>>+++++[<----->-]<-[<[-]>>>+[<+<->>-]<[>+<-]<[<++>>>+[<+<+>>-]<[>+<-]]>[<]

<]>>[-]<<<[[-]<<[>>+>+<<<-]>>[<<+>>-]+>------------[<[-]>>>+[<+<->>-]<[>+<-]<[<

++>>>+[<+<+>>-]<[>+<-]]>[<]<]>>[-]<<<<<------------->>[[-]+++++[<<+++++>>-]<<+>

>]<[>++++[<<++++++++>>-]<-]>]<[-]++++++++[<++++++++>-]<+>]<.[-]+>>+<]>[[-]<]<]

bf.py

mcandre (Andrew Pennebaker) — Mon, 19 Feb 2007 00:52:20 GMT

// Brainfuck Interpreter



#!/usr/bin/env python



"""A Brainfuck interpreter"""



__author__="Andrew Pennebaker (andrew.pennebaker@gmail.com)"

__date__="18 Nov 2005 - 27 Feb 2006"

__copyright__="Copyright 2006 Andrew Pennebaker"

__license__="GPL"

__version__="0.5"

__URL__="http://snippets.dzone.com/posts/show/3536"



from aio import chomp



import sys

from getopt import getopt



tape=[0]*100

address=0



def sublevel(toplevel):

	i=0



	# until a balanced-bracket code block is found, add a character



	while toplevel[0:i+1].count("[")!=toplevel[0:i+1].count("]"): i+=1



	return toplevel[1:i]



def run(instructions):

	global tape

	global address



	position=0

	while position		cmd=instructions[position]



		if cmd=="<": address-=1

		elif cmd==">": address+=1

		elif cmd=="+": tape[address]+=1

		elif cmd=="-": tape[address]-=1

		elif cmd==".": sys.stdout.write(chr(tape[address]))

		elif cmd==",":

			try: tape[address]=ord(sys.stdin.read(1))

			except: tape[address]=-1

		elif cmd=="[":

			level=sublevel(instructions[position:])

			while tape[address]!=0: run(level)



			position+=len(level)+1



		position+=1



def usage():

	print "Usage: %s [options] " % (sys.argv[0])

	print "--help (usage)"



	sys.exit()



def main():

	systemArgs=sys.argv[1:] # ignore program name



	live=False



	optlist=[]

	args=[]



	try:

		optlist, args=getopt(systemArgs, None, ["help"])

	except Exception, e:

		usage()



	live=len(args)<1



	for option, value in optlist:

		if option=="--help":

			usage()



	if live:

		print "--BF Interpreter 0.5--"

		print "  Type exit to exit."



		line="not exit"

		while line!="exit":

			sys.stdout.write("% ")

			line=chomp(sys.stdin.readline())



			if line.count("[")!=line.count("]"):

				raise "Unbalanced brackets"

			else:

				run(line)

	else:

		src=args[0]



		srcfile=open(src, "r")

		code="".join(srcfile.readlines())

		srcfile.close()



		if code.count("[")!=code.count("]"):

			raise "Unbalanced brackets"

		else:

			run(code)



if __name__=="__main__":

	try:

		main()

	except KeyboardInterrupt, e:

		pass