Erlang入门：构建application练习题1

Erlang入门：构建application练习1

1、定义application回调模块

%% 文件名为bank_app.erl
-module(bank_app).
%% 指定behaviour为application
-behaviour(application). 
%% 导出application回调模块的函数
-export([start/2, stop/1]). 

%% 启动application时调用
start(_Type, _Args) -> 
("Start ~p ...", [?MODULE]),
{ok, self()}.

%% 停止application时调用
stop(_State) -> 
?I("Stop ~p!", [?MODULE]),
ok.

2、加载application

application:load({application, bank, [{mod, {bank_app, []}}]}).

application:load/1的参数为application的资源描述，

{application, bank, [{mod, {bank_app, []}}]}中，
指明application的名称为bank，回调模块为bank_app

application的资源描述具体定义可以参见文档：
http://www.erlang.org/doc/man/app.html

3、启动application

application:start(bank). 

4、停止application

application:stop(bank).

5、卸载application

application:unload(bank).