开始接触erlang，erlang怎么编译成一个独立运行的程序

escript可以直接执行erl源码

$ cat factorial #!/usr/bin/env escript %% -*- erlang -*-
%%! -smp enable -sname factorial -mnesia debug verbose
main([String]) ->
try
N = list_to_integer(String),
F = fac(N),
io:format("factorial ~w = ~w\n", [N,F])
catch
_:_ ->
usage()
end;
main(_) ->
usage().

usage() ->
io:format("usage: factorial integer\n"),
halt(1).

fac(0) -> 1;
fac(N) -> N * fac(N-1).

?

$ factorial 5
factorial 5 = 120
$ factorial
usage: factorial integer
$ factorial five
usage: factorial integer