var stream : int = 0
var a : char = 97
var b : char = 0
var filename : (array char) = ".foo"

fn main [
  call create, filename
  *stream <- call open, filename, 1/wronly
  call write, *stream, a, 1
  call close, *stream
  stream <- call open, filename, 0/rdonly
  call read, *stream, b, 1
  call close, *stream
  call unlink, filename
  var result/EBX : char
  result/EBX <- copy b  # TODO: copy char to int?
  call exit-EBX
]

# like exit, but assumes the code is already in EBX
fn exit-EBX [
  code/EAX <- copy 1/exit
  syscall
]