Question

似乎最常被接受的将用户从http://example.com重定向到http://www.example.com的方法是301永久重定向，但我遇到了一个似乎使用其他方法重定向的网站（Facebook）。我使用PHP内置的get_headers（）函数，它显示http://facebook.com和http://www.facebook.com返回302（Found），当我期望看到两个不同的HTTP代码（类似于200 OK和301 Permanent Redirect）。那么，如果facebook.com重定向到www.facebook.com，为什么我会看到相同的HTTP响应代码？他们可以使用哪些其他方法（不包括元刷新等明显的方法）来重定向？

以下是使用和不使用WWW前缀测试get_headers（）的两个数据数组：

Array
(
[0] => HTTP/1.0 302 Found
[1] => Location: https://facebook.com/
[2] => Content-Type: text/html; charset=utf-8
[3] => X-FB-Debug: wwltbGRu1BTbywd3gta2SdLc+wpyGdq51OOfn2wGKPs=
[4] => Date: Tue, 30 Apr 2013 06:46:59 GMT
[5] => Connection: close
[6] => Content-Length: 0
[7] => HTTP/1.0 301 Moved Permanently
[8] => Location: https://www.facebook.com/
[9] => Content-Type: text/html; charset=utf-8
[10] => X-FB-Debug: WxvPFmdvhZu01Ksi4H9ttx0nffFCraY9TQtxscHgRlU=
[11] => Date: Tue, 30 Apr 2013 06:47:00 GMT
[12] => Connection: close
[13] => Content-Length: 0
[14] => HTTP/1.0 302 Found
[15] => Location: http://www.facebook.com/unsupportedbrowser
[16] => P3P: CP="Facebook does not have a P3P policy. Learn why here: http://fb.me/p3p"
[17] => X-Content-Type-Options: nosniff
[18] => Set-Cookie: datr=5Gh_Ue6q0jyzse8jKRbcPg2N; expires=Thu, 30-Apr-2015 06:47:00 GMT; path=/; domain=.facebook.com; httponly
[19] => Content-Type: text/html; charset=utf-8
[20] => X-FB-Debug: 3lKH0JMHOjd/q5qzs0s6h+WJdk0YnQG67DhnqJa7D3Q=
[21] => Date: Tue, 30 Apr 2013 06:47:00 GMT
[22] => Connection: close
[23] => Content-Length: 0
[24] => HTTP/1.0 200 OK
[25] => Cache-Control: private, no-cache, no-store, must-revalidate
[26] => Expires: Sat, 01 Jan 2000 00:00:00 GMT
[27] => P3P: CP="Facebook does not have a P3P policy. Learn why here: http://fb.me/p3p"
[28] => Pragma: no-cache
[29] => X-Content-Type-Options: nosniff
[30] => X-Frame-Options: DENY
[31] => X-XSS-Protection: 0
[32] => Set-Cookie: datr=5Gh_URQUdhoRh4w74JHDNmtA; expires=Thu, 30-Apr-2015 06:47:00 GMT; path=/; domain=.facebook.com; httponly
[33] => Set-Cookie: reg_ext_ref=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; path=/; domain=.facebook.com
[34] => Set-Cookie: reg_fb_gate=http%3A%2F%2Fwww.facebook.com%2Funsupportedbrowser; path=/; domain=.facebook.com
[35] => Set-Cookie: reg_fb_ref=http%3A%2F%2Fwww.facebook.com%2Funsupportedbrowser; path=/; domain=.facebook.com
[36] => Content-Type: text/html; charset=utf-8
[37] => X-FB-Debug: poI8PSRn+KNx3GnMc+8ZcZzsWFncr28gewEWkLisCbc=
[38] => Date: Tue, 30 Apr 2013 06:47:00 GMT
[39] => Connection: close
[40] => Content-Length: 19409
)
Array
(
[0] => HTTP/1.0 302 Found
[1] => Location: https://www.facebook.com/
[2] => Content-Type: text/html; charset=utf-8
[3] => X-FB-Debug: duXMWSWa3Fr5k98z6Ze/HkXeYG5qY8tRuhvCEXg/6wQ=
[4] => Date: Tue, 30 Apr 2013 06:47:00 GMT
[5] => Connection: close
[6] => Content-Length: 0
[7] => HTTP/1.0 302 Found
[8] => Location: http://www.facebook.com/unsupportedbrowser
[9] => P3P: CP="Facebook does not have a P3P policy. Learn why here: http://fb.me/p3p"
[10] => X-Content-Type-Options: nosniff
[11] => Set-Cookie: datr=5Wh_UUqT6BOIQhG3lvSCTnUI; expires=Thu, 30-Apr-2015 06:47:01 GMT; path=/; domain=.facebook.com; httponly
[12] => Content-Type: text/html; charset=utf-8
[13] => X-FB-Debug: B7P9WpeO6QRPr3g+7D/b6w3ssnJMGVa3AXd3qaG6UOA=
[14] => Date: Tue, 30 Apr 2013 06:47:01 GMT
[15] => Connection: close
[16] => Content-Length: 0
[17] => HTTP/1.0 200 OK
[18] => Cache-Control: private, no-cache, no-store, must-revalidate
[19] => Expires: Sat, 01 Jan 2000 00:00:00 GMT
[20] => P3P: CP="Facebook does not have a P3P policy. Learn why here: http://fb.me/p3p"
[21] => Pragma: no-cache
[22] => X-Content-Type-Options: nosniff
[23] => X-Frame-Options: DENY
[24] => X-XSS-Protection: 0
[25] => Set-Cookie: datr=5Wh_Ud4XwmSGX2Uxzg_KAHgW; expires=Thu, 30-Apr-2015 06:47:01 GMT; path=/; domain=.facebook.com; httponly
[26] => Set-Cookie: reg_ext_ref=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; path=/; domain=.facebook.com
[27] => Set-Cookie: reg_fb_gate=http%3A%2F%2Fwww.facebook.com%2Funsupportedbrowser; path=/; domain=.facebook.com
[28] => Set-Cookie: reg_fb_ref=http%3A%2F%2Fwww.facebook.com%2Funsupportedbrowser; path=/; domain=.facebook.com
[29] => Content-Type: text/html; charset=utf-8
[30] => X-FB-Debug: 4HXkUp4MHgy+i8qppuZvbHhYH6F4xQlfl0mUNrpj5hY=
[31] => Date: Tue, 30 Apr 2013 06:47:01 GMT
[32] => Connection: close
[33] => Content-Length: 19409
)

Answer 1

如果您https://facebook.com/没有www，请先将您重定向到https://www.facebook.com/，然后检查您的浏览器（如果使用curl，请检查您的用户代理，...放一个典型的浏览器用户像Chrome这样的代理商）如果不支持将您重定向到http://www.facebook.com/unsupportedbrowser但是如果你带https://www.facebook.com/，那么请检查你的浏览器（如果使用curl，检查你的用户代理，...放一个典型的浏览器用户代理，如chrome ）如果不支持将您重定向到http://www.facebook.com/unsupportedbrowser

此页面解释了http状态代码定义

注意注意我认为是你的答案

http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

10.3.2 301永久移动

已为所请求的资源分配了一个新的永久URI和any   以后对此资源的引用应该使用其中一个返回的   的URI。具有链接编辑功能的客户端应该自动进行   将对Request-URI的引用重新链接到一个或多个新的   尽可能由服务器返回的引用。这个回应是   除非另有说明，否则可缓存。

新的永久URI应该由位置字段给出   响应。除非请求方法是HEAD，否则是实体   响应应该包含一个带有超链接的短超文本注释   新的URI。

如果收到301状态代码以响应除以外的请求   GET或HEAD，用户代理不得自动重定向   除非可以由用户确认，否则请求，因为这可能   改变发出请求的条件。
  Note: When automatically redirecting a POST request after
  receiving a 301 status code, some existing HTTP/1.0 user agents
  will erroneously change it into a GET request.
10.3.3 302找到了

请求的资源暂时驻留在不同的URI下。   由于重定向有时可能会改变，客户端应该这样做   继续使用Request-URI用于将来的请求。这个回应是   如果由Cache-Control或Expires标头指示，则仅可缓存   字段。

临时URI应该由位置字段给出   响应。除非请求方法是HEAD，否则是实体   响应应该包含一个带有超链接的短超文本注释   新的URI。

如果收到302状态代码以响应除以外的请求   GET或HEAD，用户代理不得自动重定向   除非可以由用户确认，否则请求，因为这可能   改变发出请求的条件。
  Note: RFC 1945 and RFC 2068 specify that the client is not allowed
  to change the method on the redirected request.  However, most
  existing user agent implementations treat 302 as if it were a 303
  response, performing a GET on the Location field-value regardless
  of the original request method. The status codes 303 and 307 have
  been added for servers that wish to make unambiguously clear which
  kind of reaction is expected of the client.

解析WWW URL前缀的不同方法

1 个答案: