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session_start 应该总是被调用吗？

[英]Should session_start always be called?

原文 2020-12-16 16:11:59 6 1 php/ session/ session-state

I noticed that there's a tmp/ folder on my webserver that contains thousands and thousands of session-id files.我注意到我的网络服务器上有一个 tmp/ 文件夹，其中包含成千上万个 session-id 文件。 So I thought it's probably better to only call session_start() when I am actually writing something into the session (login) and then only call it, if there's a logged in user active.所以我认为最好只在我实际向 session （登录）写入内容时调用 session_start() ，然后仅在有登录用户处于活动状态时才调用它。

I couldn't find too much on the topic (and I'm not sure if what I'm trying to accomplish is possible even), just a couple of people saying that session_start() should always be called.我在这个话题上找不到太多（而且我不确定我想要完成的工作是否可行），只有几个人说 session_start() 应该总是被调用。 Does that make sense?那有意义吗？ And isn't it a performance issue if all these session-ids are stored?如果存储了所有这些会话 ID，这不是性能问题吗？

1 个解决方案

So I thought it's probably better to only call session_start() when I am actually writing something into the session (login) and then only call it, if there's a logged in user active.所以我认为最好只在我实际向 session （登录）写入内容时调用 session_start() ，然后仅在有登录用户处于活动状态时才调用它。

If you set up a login system in any vaguely traditional way that involves sessions, there is no way to tell if you have a logged in user without calling session_start .如果您以任何涉及会话的模糊传统方式设置登录系统，则如果不调用session_start就无法判断您是否有登录用户。

just a couple of people saying that session_start() should always be called.只有几个人说 session_start() 应该总是被调用。 Does that make sense?那有意义吗？

Yes.是的。 If you are going to interact with a session — be it to write to the session, or read from it — then call session_start() .如果您要与 session 交互——无论是写入 session，还是从中读取——然后调用session_start() 。

Most websites that deal with login sessions will put a "You are logged in as Bob: click here to logout" or "You are not logged in: click here to log in" message on every page, so most websites will need to call sessions_start() on every page.大多数处理登录会话的网站都会在每个页面上放置“您以 Bob 身份登录：单击此处注销”或“您未登录：单击此处登录”消息，因此大多数网站需要调用sessions_start()在每一页上。

And isn't it a performance issue if all these session-ids are stored?如果存储了所有这些会话 ID，这不是性能问题吗？

No.不。

It has a performance impact , but that impact is probably negligible.它对性能有影响，但这种影响可能可以忽略不计。 If it becomes a problem, worry about it then.如果它成为一个问题，然后担心它。

Don't try to solve performance problems you don't have.不要试图解决你没有的性能问题。