Php header() function and its common uses_PHP tutorial

Grammar:

Send raw

to client

Note:

The

Header

Parameter description:

参数	描述
string	必需。规定要发送的报头字符串。
replace	可选。指示该报头是否替换之前的报头，或添加第二个报头。 默认是
http_response_code	可选。把

Parameters

Description

string

Required. Specifies the header string to be sent.

状态码	说明
100-199	表示成功接收请求，要求客户端继续提交下一次请求才能完成整个处理过程
200-299	成功接收请求，并已完成整个处理过程，常用
300-399	未完成请求，客户端需要进一步细化请求，比如，请求的资源已经移动到一个新的地址，常用
400-499	客户端请求有误 常用
500-599	服务器端出现错误，常用

replace

Optional. Indicates whether this header replaces the previous header, or adds a second header. Default is

http_response_code

Optional. Force the

Common usage examples: 1. Send server status code header("HTTP/1.0 404 Not Found"); Common status codes

Status code	Description
100-199	indicates that the request was successfully received and the client is required to continue submitting the next request to complete the entire processing process
200-299	The request was successfully received and the entire processing process has been completed. Commonly used
300-399	The request is not completed and the client needs to further refine the request. For example, the requested resource has been moved to a new address. Commonly used
400-499	Incorrect client request Commonly used
500-599	An error occurred on the server side, commonly used

2. Page jump

Jump after 3s

3. Set browser cache

Force the browser not to cache!

<span //</span><span header("Expires:-1");</span>

<span header</span>("Expires: Mon, 26 Jul 1997 05:00:00 GMT"<span );

</span><span header</span>("Cache-Control:no-cache,must-revalidate"<span );

</span><span header</span>("pragma:no-cache"<span );

</span><span header</span>("Last-Modified: ". <span date</span>("D, j M Y H:i:s T") );

Description

The time after

Expiresgmdate("M d Y H:i:s");

Common values ​​for

Cache-control include

Cache-directive	说明
public	所有内容都将被缓存
private	内容只缓存到私有缓存中
no-cache	所有内容都不会被缓存
no-store	所有内容都不会被缓存到缓存或
must-revalidation/proxy-revalidation	如果缓存的内容失效，请求必须发送到服务器
max-age=xxx (xxx is numeric)	缓存的内容将在

Cache-directive<🎜>

<🎜>Description<🎜>

<🎜>public<🎜>

<🎜>All content will be cached<🎜>

<🎜>private<🎜>

<🎜>Content is only cached in private cache<🎜>

<🎜>no-cache<🎜>

<🎜>No content will be cached<🎜>

<🎜>no-store<🎜>

<🎜>No content will be cached in cache or <🎜>

<🎜>must-revalidation/proxy-revalidation<🎜>

<🎜>If cached content becomes invalid, the request must be sent to the server <🎜>

<🎜>max-age=xxx (xxx is numeric)<🎜>

<🎜>Cached content will expire in <🎜>

1.Open a new window

If the value of specifying

Header(“cache-control:max-age=5”);

means that the server will not be accessed again within

2. Enter in the address bar

If the value is private

If the value is

will be accessed repeatedly every time

No matter what the value is, it will be visited repeatedly

When the < span Temporary article folder leaves page backup.

In addition, caching will also be affected by specifying the "

Expires: Fri, 31 Dec 1999 16:00:00 GMT

5."Last-Modified

When the browser requests a certain The attribute of
　
When the client requests this
　
If the server-side resources have not changed, the

Smart developers will use
The process is as follows

1 The client requests a page (

2 The server returns the page

3 The client displays the page and caches the page together with

4 The client requests the page

5 The server checks the

3.文件下载

比如下载一个

<span //</span><span  We'll be outputting a PDF</span>

<span header</span>('Content-type: application/pdf'<span );

</span><span //</span><span  It will be called downloaded.pdf

//表明他是附件，进行命名并下载</span>

<span header</span>('Content-Disposition: attachment; filename="downloaded.pdf"'<span );

</span><span //</span><span  The PDF source is in 1.pdf</span>

<span readfile</span>('1.pdf');

一般

<span header</span>(&ldquo;content-type:application/octet-<span sream&rdquo;);

</span><span Header</span>(&ldquo;Accept-Ranges:bytes&rdquo;);<span //</span><span 依字节返回</span>

<span Header</span>(&ldquo;content-disposition:attachement;filename=<span &rsquo; 文件名&rsquo;&rdquo;);

</span><span Header</span>(&ldquo;Accept-length:&rdquo;.<span $filesize</span>);

 

 其实要更好的了解这些，还是得去好好学习http协议啊！

参考资料:互联网....

 

http://www.bkjia.com/PHPjc/440172.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/440172.htmlTechArticle语法： 向客户端发送原始的 需注意： Header 参数说明： 参数 描述 string 必需。规定要发送的报头字符串。 replace 可选。指示该报头是否替...