PHP HTTP Functions

header()

Sends a raw HTTP header to a client

headers_list()

Returns a list of response headers sent (or ready to send)

headers_sent()

Checks if / where the HTTP headers have been sent

setcookie()

Defines a cookie to be sent along with the rest of the HTTP headers

setrawcookie()

Defines a cookie (without URL encoding) to be sent along with the rest of the HTTP headers