PHP Tip #5: header
Another useful command that all PHP coders should know is the header() function. You can use it to send a HTTP header to the server.
As an example you could use it to redirect to a certain webpage if a certain string of conditions are true, just like this:
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if($error == true) { header('Location: /path/to/error/page'); } |
You can also use it to send a 404 header. This is useful when using an index.php file as a URL router, similar to PHP frameworks like Codeigniter, if a file isn’t found you could get the index.php file to send a 404 header & then include a pre-made 404 page. Something like this always works for me:
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header("HTTP/1.0 404 Not Found"); header("Status: 404 Not Found"); |
There is one massively important thing to remember. You can only use the header() function before you have output anything to the browser. For example the following will work:
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header("HTTP/1.0 404 Not Found"); header("Status: 404 Not Found"); echo '404'; |
Where as this will not work:
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echo '404'; header("HTTP/1.0 404 Not Found"); header("Status: 404 Not Found"); |
I hope that helps those who are unfamiliar with the header() function. 🙂
