一旦设置，如何在Erlang httpc客户端默认配置文件中取消设置或删除代理选项？

Question

代理最初未设置并显示为undefined：

httpc:get_options(all).
{ok,[{proxy,{undefined,[]}},
     {https_proxy,{undefined,[]}},
     {pipeline_timeout,0},
     {max_pipeline_length,2},
     {max_keep_alive_length,5},
     {keep_alive_timeout,120000},
     {max_sessions,2},
     {cookies,disabled},
     {verbose,false},
     {ipfamily,inet},
     {ip,default},
     {port,default},
     {socket_opts,[]},
     {unix_socket,undefined}]}

我可以毫无问题地设置代理选项：

httpc:set_options([{proxy, {{"www-proxy.mycompany.com", 8000},["localhost"]}}]).

在不需要代理时，如何取消未定义代理（或没有代理）？我试过了：

httpc:set_options([{proxy,{undefined, []}}]).
But it throws an exception:
** exception throw: {error,{bad_option,proxy,{undefined,[]}}}
     in function  httpc:bad_option/2 (httpc.erl, line 1102)
     in call from httpc:validate_options/2 (httpc.erl, line 932)
     in call from httpc:validate_options/1 (httpc.erl, line 922)
     in call from httpc:set_options/2 (httpc.erl, line 236)

我究竟做错了什么？

Answer 1

你传递给函数的参数格式是错误的。正确的格式是

httpc:set_options([{proxy, {{"", 0},[]}}]).

现在代理主机将是“”：0。但我不知道你的任务是否可以接受。

对评论的回应：尝试将'proxy'选项直接设置为http_manager而不是杀死他：

httpc_manager:set_options([{proxy,{undefined, []}}],httpc_manager).

看看erlang shell：

1> inets:start().
ok
2> httpc:set_options([{proxy, {{"www-proxy.mycompany.com", 8000},["localhost"]}}]).
ok
3> httpc:get_options(all).
{ok,[{proxy,{{"www-proxy.mycompany.com",8000},
             ["localhost"]}},
     {https_proxy,{undefined,[]}},
     {pipeline_timeout,0},
     {max_pipeline_length,2},
     {max_keep_alive_length,5},
     {keep_alive_timeout,120000},
     {max_sessions,2},
     {cookies,disabled},
     {verbose,false},
     {ipfamily,inet},
     {ip,default},
     {port,default},
     {socket_opts,[]},
     {unix_socket,undefined}]}
4> httpc_manager:set_options([{proxy,{undefined, []}}],httpc_manager).
ok
5> httpc:get_options(all).                                            
{ok,[{proxy,{undefined,[]}},
     {https_proxy,{undefined,[]}},
     {pipeline_timeout,0},
     {max_pipeline_length,2},
     {max_keep_alive_length,5},
     {keep_alive_timeout,120000},
     {max_sessions,2},
     {cookies,disabled},
     {verbose,false},
     {ipfamily,inet},
     {ip,default},
     {port,default},
     {socket_opts,[]},
     {unix_socket,undefined}]}