What is a raw http header?"

[Sunking]

Hi,

I have a simple question.
What is a "raw http header?"

Also, I can't seem to figure out what the header function does.

Thanks

[Pig]

OMG Billett, RTFM. Disregard what billett wrote.

A http header is information sent to the browser. It can be an image, a page, etc. Sorry for the vague definition; just google for it.

header() is used to send such a header to the browser. One of the more useful applications is to send a location header, that redirects the browser to a different page. Look at the user contributed notes for the function to get an idea.
http://us2.php.net/header

[yelvington]

Here's how HTTP works.

Browser sends a request in a specified format.

Server responds with:

1) HTTP headers

and, if appropriate

2) Body (stream of bytes, which might be HTML, a jpeg, a downloadable file)

Headers might look like this

HTTP/1.1 200 OK
Date: Wed, 11 Feb 2004 21:10:14 GMT
Server: Apache/2.0.45 (Unix) mod_ssl/2.0.45 OpenSSL/0.9.6b PHP/4.3.1
Accept-Ranges: bytes
X-Powered-By: PHP/4.3.1
Connection: close
Content-Type: text/html; charset=ISO-8859-1

Notice the first header, which means "OK." It might instead be result code 404, which means "no such document." Or 301, which means "moved permanently."

If you do this:

header('Location: http://www.yahoo.com/');

the server will emit code 301 and will include your explicit location line among the header lines. A browser will consider that a "redirect" instruction and will go get the new URL.