erlang本身提供一个接口,可以用来检查模块是否有导出函数,这个接口是erlang:function_exported/3,但是很多时候这个接口无法正常使用。 下面重现一下这个问题: 1> erlang:function_exported(crypto,start,0). false 2> crypto:start(). ok 3> erlang:function_exported(crypto,start,0). true 注意:例子中并不是说一...
这个接口是用来检查模块函数是否导出,但是,如果模块没加载过,这个函数返回值就是false 3> erlang:function_exported(odbc,start,0). false 4> odbc:start(). ok 5> erlang:function_exported(odbc,start,0). true 我之前也讨论过这个问题,解决方案看这里 erlang:list_to_binary() 如果参数是多层嵌套结构,就会...
A concept to understand is that Erlang has bothlocalandexternalcalls. Local calls are those function calls you can make with functions that might not be exported. They're just of the formatAtom(Args). An external call, on the other hand, can only be done with exported functions and has th...
erlang:function_exported/3检测一个函数是否输出并被加载 erlang:garbage_collect/0对当前进程进行垃圾回收操作 erlang:garbage_collect/1对指定进程进行垃圾回收操作 erlang:get/0返回进程里的所有字典值 erlang:get/1从进程字典里获取一个值 erlang:get_cookie/0获取本地节点的魔饼值(magic cookie) erlang:get_keys...
case erlang:function_exported(Module, test, 0) of true -> io:format(" - Calling ~p:test() ...", [Module]), case catch Module:test() of ok -> io:format(" ok.~n"), reload; Reason -> io:format(" fail: ~p.~n", [Reason]), ...
function_exported/3 garbage_collect/0 garbage_collect/1 get/0 get/1 get_cookie/0 get_keys/1 get_module_info/2 get_stacktrace/0 group_leader/0 group_leader/2 hd/1 insert_element/3 integer_to_binary/1 integer_to_binary/2 integer_to_list/1 ...
A last function will be added to the module, using both functions add/2 and hello/0:greet_and_add_two(X) -> hello(), add(X,2).Do not forget to add greet_and_add_two/1 to the exported function list. The calls to hello/0 and add/2 don't need to have the module name ...
%% Onlythisfunctionisexported format_temps([])-> % No outputforan empty list ok; format_temps([City | Rest]) -> print_temp(convert_to_celsius(City)), format_temps(Rest). convert_to_celsius({Name, {c, Temp}}) -> % No conversion needed ...
Erlang 的内置函数 spawn 可以用来创建一个新的进程: spawn(Module, Exported_Function, List of Arguments)。假设有如下这样一个模块: -module(tut14). -export([start/0, say_something/2]). say_something(What, 0) -> done; say_something(
Erlang内置函数spawn用于创建一个新进程:spawn(Module, Exported_Function, List of Arguments)。考虑下面的模块 -module(tut14).-export([start/0,say_something/2]).say_something(What,0)->done;say_something(What,Times)->io:format("~p~n",[What]),say_something(What,Times-1).start()->spawn(tut...