Header function usage

Header is the string sent by the server before the server passes HTML data to the browser with HTTP co-meaning. in the header <br/> and the header of the HTML file (header) it is a string sent by the server before passing HTML data to the browser with HTTP co-meaning. in the header
Separate HTML files with a blank line. For more information about HTTP, see the RFC 2068 official file.
Http://www.w3.org/Protocols/rfc2068/rfc2068 ). Before Sending HTML data back to PHP, you must first
All the headers are uploaded.

Note: The traditional header must contain one of the following three headers and can only appear once.

Content-Type: xxxx/yyyy
Location: xxxx: yyyy/zzzz
Status: nnn xxxxxx

The new Multipart MIME type can appear more than twice.

Example

Example 1: In this example, the browser is redirected to the official PHP website.
Header ("Location: http://www.php.net ");
Exit;
>?

Example 2: to obtain the latest data every time, instead of the data in the Proxy or cache, you can use the following header
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 ");
>?

Example 3: make the user's browser unable to find the file information.
Header ("Status: 404 Not Found ");
>?

Example 4: allow users to download files.

Header ("Content-type: application/x-gzip ");
Header ("Content-Disposition: attachment; filename = file name ");
Header ("Content-Description: PHP3 Generated Data ");
>?