bf.c

#include <stdio.h>
char b[30000],z[9999],*p=b,c,*a,i;
f(char*r,int s)
{
    while(c=*a++)
    {   
        if(!s)
        {
            (c-62)?(c-60)?(c-43)?(c-45)?(c-46)?(c-44)?0:(*p=getchar()):putchar(*p):--*p:++*p:--p:++p;
            if(c==91)f(a,!*p);
            else if(c==93){if(!*p)return;else a=r;}
        }
        else
        {
            if(c==93)
            {
                --s;
                if(!*p&&!s)return;
            }
            else if(c==91)
            {
                s++;
            }
        }
    }
}

main(int c,char**v){
    fread(z,1,9999,fopen(*++v,"r"));
    a=z;
    f(0,0);
}

bf.hs

import IO
import System
z=return
'>'#(c,(l,d:r))=z(d,(c:l,r))
'<'#(d,(c:l,r))=z(c,(l,d:r))
'+'#(c,m)=z(succ c,m)
'-'#(c,m)=z(pred c,m)
'.'#t@(c,_)=putChar c>>hFlush stdout>>z t
','#(_,m)=getChar>>=(\c->z(c,m))
_#t=z t
_%t@('\0',_)=z t
i%t=i t>>=(i%)
b('[':r)=k$b r
b(']':r)=(z,r)
b(c:r)=f(c#)$b r
b[]=(z,[])
f j(i,r)=(\t->j t>>=i,r)
k(i,r)=f(i%)$b r
main=getArgs>>=readFile.head>>=($('\0',("",repeat '\0'))).fst.b

bf.lua

-- >    increment the data pointer (to point to the next cell to the right).
-- <    decrement the data pointer (to point to the next cell to the left).
-- +    increment (increase by one) the byte at the data pointer.
-- -    decrement (decrease by one) the byte at the data pointer.
-- .    output a character, the ASCII value of which being the byte at the data pointer.
-- ,    accept one byte of input, storing its value in the byte at the data pointer.
-- [    if the byte at the data pointer is zero, then instead of moving the instruction pointer forward to the next command, jump it forward to the
--      command after the matching ] command*.
-- ]    if the byte at the data pointer is nonzero, then instead of moving the instruction pointer forward to the next command, jump it back to the
--      command after the matching [ command*.
s=setmetatable({0},{__index=function() return 0 end})

i=1 -- index array
j=1 -- index input
l=loadstring
t="><+-.,[]"
o=0
fh=arg[1] and io.open(arg[1]) or io.stdin
I=fh:read"*a":gsub("[^><%+%-%.,%[%]]","")
fh:close()
print(I)
for k=1,#I do io.write(k%5==1 and"+"or"-") end
io.write"\n"
for k=1,math.ceil(#I/5) do local n=5*(k-1)+1 local s=(" "):rep(4-math.floor(math.log10(n))) io.write(n,s) end
io.write"\n"
dbg=true
f={
"i=i+1 ",   -- array index ++
"i=i-1 ",   -- array index --
"s[i]=(s[i]+1)%256 ",   -- byte + 1
"s[i]=(s[i]-1)%256 ",   -- byte - 1
"io.write(string.char(s[i])) ", -- put byte
"local c=io.read(1):byte()s[i]=c==10 and s[i] or c",        -- read byte "Newline required!"
[=[if s[i]==0 then
    o=0
    repeat
        if dbg then print(j,"Forward!",o,b) end
        b=I:sub(j,j):match'[%[%]]'
        o= b=='['and o+1 or b==']' and o-1 or o;
        j=j+1
    until b==']' and o == 0
end
]=],    -- jump to matching ]
[=[
if s[i]~=0 then
    o=0
    count=0
    repeat 
        if dbg then print(j,"Backwards",o,b) end
        b=I:sub(j,j):match"[%[%]]"
        o= b=='['and o-1 or b==']' and o+1 or o;
        j=j-1
    until b=='[' and o == 0
end
]=],    -- jump to matching ]
}
for k,v in ipairs(f) do f[t:sub(k,k)],e=l(v) if e then error(e)end end
function run()
j=1
while j<=#I do
    f[I:sub(j,j)]()
    j=j+1
end
end
res,err = pcall(run)
if not res then
    print('error=',err)
    print('Dumping state')
    print('','stack')
    for k,v in pairs(s) do print("",k,v) end
end
if debug then
    print("stack")
    for k,v in pairs(s) do print(k,v) end
end

bf.ocaml

{let a=Array.create 30000 0
let(%)f g h=f(g h)
let s v i=a.(i)<-v;i
let o d i=s(a.(i)+d)i
let p i=print_char(Char.chr a.(i));flush stdout;i
let r i=s(Char.code(input_char stdin))i
let rec w g i=if 0=a.(i)then i else w g(g i)
let n x=x}
rule t f=parse
|'>'{t(succ%f)lexbuf}
|'<'{t(pred%f)lexbuf}
|'+'{t((o 1)%f)lexbuf}
|'-'{t((o(-1))%f)lexbuf}
|'.'{t(p%f)lexbuf}
|','{t(r%f)lexbuf}
|'['{t((w(t n lexbuf))%f)lexbuf}
|']'|eof{f}
|_{t f lexbuf}
{let _=t n(Lexing.from_channel(open_in Sys.argv.(1)))0}

bf.pl

$_=q('>;$p++;<;$p--;+;D++;-;D--;[;while(D){;];};.;print chrD;,;D=ord getc');
s[D]'$b[$p]'g;s/;/','/g;%c=eval;$/=$,;$_=<>;s/./$c{$&};/g;eval

<<END

$ perl bf.pl hello.bf
Hello World!
$ perl bf.pl prime.bf
Primes up to: 100
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

END

bf.py

import sys
i=0
b=[0]*30000
t=''
for e in open(sys.argv[1]).read():
 t+=' '*i+['i+=1','i-=1','b[i]+=1','b[i]-=1','sys.stdout.write(chr(b[i]))','b[i]=ord(sys.stdin.read(1))','while b[i]:','pass','']['><+-.,['.find(e)]+'\n'
 i+=(92-ord(e))*(e in'][')
exec t 

bf.rb

code = "a = [0] * 3e4; i = 0;"
more_code ARGF.bytes.map {|b|
  replacements = {
    ?. => "putc a[i]",
    ?, => "a[i] = getc",
    ?[ => "while a[i] > 0 do",
    ?] => "end",
    ?< => "i -= 1",
    ?> => "i += 1",
    ?+ =>"a[i]+=1",
    ?- =>"a[i]-=1"
  }
  replacements[b]
}.join(";")
eval code+more_code

bf2.c

#include <stdio.h>
main(int c,char**v){
    int m[3000],s[99],p=0,i=0,n=0;
    char l[9999],d;
    FILE*f=fopen(v[1],"r");
    for(l[i]=0;i<9999&&l[i]!=EOF;l[i]=getc(f))i++;
    for(i=1;d=l[i];i++){
        if(!n){ // > < + - . , ] \n [ ]
            p+=d-62?0:1;
            p-=d-60?0:1;
            m[p]+=d-43?0:1;
            m[p]-=d-45?0:1;
            if(d==46)putchar(m[p]);
            if(d==44){m[p]=getchar();}
            if(d==93){i=s[c]-1;c--;n++;}
        }
        if(d==91){if(m[p]){c++;s[c]=i;}else{n++;}}
        n-=d-93?0:1;
    }
}

Gold.