erlang中判断进程是否存活

一个参数的方法是已知Pid判断进程是否存活。两个参数的方法是已知节点和Pid或进程名判断进程是否存活。

is_process_alive(Pid) when is_pid(Pid) ->
    rpc:call(node(Pid), erlang, is_process_alive, [Pid]);
is_process_alive(_Pid) ->
    false.


is_process_alive(undefined, _ProcName) ->
    false;
is_process_alive(_Node, undefined) ->
    false;
is_process_alive(Node, Pid) when is_pid(Pid) ->
    case rpc:call(Node, erlang, is_process_alive, [Pid]) of
        undefined ->
            false;
        _Pid ->
            true
    end;
is_process_alive(Node, ProcName) ->
    case rpc:call(Node, erlang, whereis, [ProcName]) of
        undefined ->
            false;
        _Pid ->
            true
    end.