First commit, trying to use Cs version of printf

prueba.jl

@@ -0,0 +1,50 @@
+module prueba
+using Base.Grisu
+export @printf, @sprintf
+
+### external printf interface ###
+
+_is_str_expr(ex) =
+isa(ex,Expr) && ex.head==:macrocall && isa(ex.args[1],Symbol) &&
+(ex.args[1] == :str || endswith(string(ex.args[1]),"_str"))
+
+macro printf(args...)
+  if length(args) == 0
+    error("@printf: called with zero arguments")
+  end
+  if !isa(args[1],String) && !(length(args) > 1 && isa(args[2],String))
+    if _is_str_expr(args[1]) || length(args) > 1 && _is_str_expr(args[2])
+      error("format must be a plain static string (no interpolation or prefix)")
+    end
+    error("first or second argument must be a format string")
+  end
+  local io, fmt
+  if isa(args[1],String)
+    io = :(Base.STDOUT)
+    args = args[1:]
+  else
+    io = args[1]
+    args = args[2:]
+  end
+  args_type = typeof(args) 
+  at = Expr(:tuple)
+  at.args = Array(Any,length(args_type))
+  at.args[1] = Expr(:curly)
+  at.args[1].args = Array(Any, 2)
+  at.args[1].args[1] = :Ptr
+  at.args[1].args[2] = :Uint8
+  for ii in 2:length(args_type)
+    at.args[ii] = symbol("$(args_type[ii])")
+  end
+
+#   ex = :(ccall( (:printf, "libc"), Int32, $at, $(args...)) )
+#   eval(ex)
+
+  return args_type, args, at
+end
+
+macro sprintf(args...)
+  :(sprint(io->@printf(io,$(map(esc,args)...))))
+end
+
+end # module