PHP header function usage and precautions, phpheader function details

PHP header function usage and precautions, phpheader function details

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

Below are some usage of headers:

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

Header ('location: '. $ url );

$ Url is the url to be redirected.

　　Note the following points for this usage:

• There must be no 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 why );

• There cannot be any output before using the header (Note: As we all know, if there is any output before the header, including blank, the error "header already sent by xxx" will appear );

• The content after the header will be executed;

2. Use header to declare content-type

Header ('content-type: text/html; charset = UTF-8 ');
There is nothing to say about it;

3. Use the header to return the response status code

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

The style is like this;

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

4. Use the header to perform redirection after a certain time

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

Where $ delay is the time to postpone the jump, $ url is the url to jump

For example: header ('refresh: 10; url = http://www.example.org/'); meaning jump to the http://www.eexample.org this site after 10 s

5. Use the 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 the header for download

Header ('content-Type: application/octet-stream'); // sets the Content Type header ('content-Disposition: attachment; filename = "example.zip "'); // set the MIME user to download as an attachment. If you change attachment to inline, it means to open the header online ('content-Transfer-Encoding: bin '); // set the transmission mode header ('content-Length: '.filesize('example.zip '); // set the Content Length // load the file to send: readfile('example.zip '); // read the object to be downloaded

The following describes several PHP header usage methods.

Jump page

Header ('location: '. $ url); // there is no space between Location and.

Declare content-type

Header ('content-type: text/html; charset = UTF-8 ');

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 10 s.

Browser cache Control

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 "');

Execute the download operation

Header ('content-Type: application/octet-stream'); // you can specify the Content Type.
Header ('content-Disposition: attachment; filename = "example.zip" '); // sets the MIME user as an attachment
Header ('content-Transfer-Encoding: binary '); // you can specify the transmission mode.
Header ('content-Length: '.filesize('example.zip '); // you can specify the Content Length.