dtcpvz8162 2016-08-25 14:45
浏览 219
已采纳

禁用cookie的php setcookie行为

can anyone confirm the behavior of PHP's setcookie() function when the client has cookies disabled? According to the documentation:

"If output exists prior to calling this function, setcookie() will fail and return FALSE. If setcookie() successfully runs, it will return TRUE. This does not indicate whether the user accepted the cookie."

I'm not sure what 'successfully runs' means exactly, but this leads me to believe that the implementation doesn't care about whether the client accepts the cookie, and that we shouldn't have to worry about PHP errors / warnings related to the cookie actually being set or not. Is that right?

Thanks in advance

  • 写回答

3条回答 默认 最新

  • du521521521 2016-08-25 14:53
    关注

    Cookies are sent via http header. Headers can ALWAYS be sent. Whether they're accepted/ignored is irrelevant - you can send ANY header you want.

    The only way to tell if a client has accepted a cookie is if the cookie gets sent BACK to the server by the client on its NEXT request.

    The only way setcookie() fails is if output has already started. That causes the PHP "headers already sent" warning.

    e.g. A normal HTTP server->client response looks like this:

    HTTP/1.1 200 OK
Content-type: text/html
Cookie: ...cookie data here ...

<html><body>Hi mom!</body></html>

    But if you do output first, BEFORE calling setcookie, you'd end up with something like this:

    HTTP/1.1 200 OK
Content-type: text/html

<html><body>Hi mom!</body></html>
Cookie: ... cookie data here ...

    which doesn't work. Headers are only headers when they're in the header block of the response. If they show up in the body, they're not a header - they're part of the content. That's why PHP issues the "headers already sent", and doesn't send the cookie. It can't - the train has already left the station.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(2条)

报告相同问题？

悬赏问题

  • ¥15 wegame打不开英雄联盟
  • ¥15 公司的电脑，win10系统自带远程协助，访问家里个人电脑，提示出现内部错误，各种常规的设置都已经尝试，感觉公司对此功能进行了限制（我们是集团公司）
  • ¥15 救！ENVI5.6深度学习初始化模型报错怎么办？
  • ¥30 eclipse开启服务后，网页无法打开
  • ¥30 雷达辐射源信号参考模型
  • ¥15 html+css+js如何实现这样子的效果？
  • ¥15 STM32单片机自主设计
  • ¥15 如何在node.js中或者java中给wav格式的音频编码成sil格式呢
  • ¥15 不小心不正规的开发公司导致不给我们y码，
  • ¥15 我的代码无法在vc++中运行呀，错误很多