push 
   
     ; pushes an integer to the stack
add        ; pushes the sum of the last two elements on the stack
sub        ; pushes the difference of the last two elements on the stack, also sets relevant flags
cmp        ; sets the zero flag as if it had subtracted, but doesn't actually perform subtraction
dup        ; duplicates the top of the stack
swap       ; swaps the top two elements on the stack
rotr       ; rotates top three elements right
rotl       ; same but to the left
in         ; pushes a single character of user input
out        ; outputs top element of stack as char
jnz @
   
  

    ; jumps to section if zero flag set with `cmp` or `sub` is not active
jz @
    

       ; jumps to section if zero flag is active
jmp @
     

       ; jumps to section

     
    
  

_start:
  push 64
  
loop:
  push 1
  add
  
  dup
  out
  
  dup
  push 90
  cmp
  jnz @loop
  
  push 10
  out

chmod +x ./stackfuck.py
./stackfuck.py 
   
    
nasm -f elf output.asm
ldd -m elf_i386 -s -o output output.o
./output