erlang异常--try...catch

触发异常

throw(Term)
exit(Reason)
erlang:error(Reason)

特列：exit(normal)，进程调用它所跑出的异常不会被捕获，该进程正常终止

try...catch

try
    unsafe_fun()
catch
    ErrType:Reason ->
        do_something()
end.

try...of...catch

try
    unsafe_fun()
of
    O ->
        io:format("do nothing");
    N ->
        do_something_with(N)
catch
    _:_ ->
        do_something()
end

of...之间的内容，不在try的保护范围

try...after 不管try中执行情况如何，after都会执行，这个机制通常用于资源释放

{ok, Fd} = file:open("test.txt", [read]),
try
    do_something_with_file(Fd)
after
    file:close(Fd)
end