Detailed explanation of the usage and precautions of header function in PHP, detailed explanation of phpheader function

void header ( string $string [, bool $replace = true [, int $http_response_code ]] ) : Send a raw HTTP header

Here are some ways to use headers:

1. Use the header function to jump to the page;

header('Location:'.$url);

Where $url is the URL to be redirected.

　The following points should be noted when using this method:

?There cannot be a space between Location and ":", otherwise an error will occur (Note: I just tested it. In my local environment, there is no page jump, but no error is reported. I don't know the reason);

?There cannot be any output before using the header (note: everyone knows this, if there is any output before the header, including blanks, the error header already sent by xxx will appear);

?What follows the header will still be executed;

2. Use header to declare content-type

header('content-type:text/html;charset=utf-8');
There’s nothing to say about this;

3. Use header to return response status code

　header(sprintf('%s %d %s', $http_version, $status_code, $description));

The style is like this;

For example: header('HTTP/1.1 404 Not Found');

4. Use header to perform jump after a certain time

header("Refresh: {$delay}; url={$url}");

Where $delay is the time to delay the jump, $url is the url that needs to be jumped

For example: header('Refresh: 10; url=http://www.example.org/'); means to jump to the website http://www.eexample.org after 10 seconds

5. Use header to control browser cache

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
　　header("Last-Modified: " . gmdate("D, d M Y H:i:s") . "GMT");
　　header("Cache-Control: no-cache, must-revalidate");
　　header("Pragma: no-cache");

6. Perform http verification

header('HTTP/1.1 401 Unauthorized');
header('WWW-Authenticate: Basic realm="Top Secret"');

7. Use header to download

header('Content-Type: application/octet-stream');//設(shè)置內(nèi)容類型
　　header('Content-Disposition: attachment; filename="example.zip"'); //設(shè)置MIME用戶作為附件下載 如果將attachment換成inline意思為在線打開
　　header('Content-Transfer-Encoding: binary');//設(shè)置傳輸方式
　　header('Content-Length: '.filesize('example.zip'));//設(shè)置內(nèi)容長度
　　// load the file to send:
　　readfile('example.zip');//讀取需要下載的文件

The following will introduce you to several uses of PHP header

Jump page

header('Location:'.$url); //No space between Location and ":".

Declare content-type

header('content-type:text/html;charset=utf-8');

Return response status code

header('HTTP/1.1 404 Not Found');

Execute jump after a certain time

header('Refresh: 10; url=http://www.baidu.com/'); //Jump after 10s.

Control browser cache

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . "GMT");
header("Cache-Control: no-cache, must-revalidate");
header("Pragma: no-cache");

Perform http verification

header('HTTP/1.1 401 Unauthorized');
header('WWW-Authenticate: Basic realm="Top Secret"');

Perform download operation

header('Content-Type: application/octet-stream'); //Set the content type
header('Content-Disposition: attachment; filename="example.zip"'); //Set MIME user as attachment
header('Content-Transfer-Encoding: binary'); //Set the transmission method
header('Content-Length: '.filesize('example.zip')); //Set content length