apache_request_headers() versus $_SERVER

Question

As far as I can tell, apache_request_headers() provides the same information as $_SERVER, but with slightly different keys. Why should someone ever use apache_request_headers() and not just get this information from $_SERVER? I am operating PHP 5.3.18 with Apache on Centos. Thank you

EDIT. identical data from $_SERVER and apache_request_headers()

Jun  2 08:50:53 localhost httpd: HTTP_HOST: www.badobe.com
Jun  2 08:50:53 localhost httpd: Host: www.badobe.com
Jun  2 08:50:53 localhost httpd: HTTP_USER_AGENT: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0
Jun  2 08:50:53 localhost httpd: User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0
Jun  2 08:50:53 localhost httpd: HTTP_ACCEPT: */*
Jun  2 08:50:53 localhost httpd: Accept: */*
Jun  2 08:50:53 localhost httpd: HTTP_ACCEPT_LANGUAGE: en-US,en;q=0.5
Jun  2 08:50:53 localhost httpd: Accept-Language: en-US,en;q=0.5
Jun  2 08:50:53 localhost httpd: HTTP_ACCEPT_ENCODING: gzip, deflate
Jun  2 08:50:53 localhost httpd: Accept-Encoding: gzip, deflate
Jun  2 08:50:53 localhost httpd: HTTP_REFERER: http://www.badobe.com/demo/administrator/index.php?cid=3
Jun  2 08:50:53 localhost httpd: Referer: http://www.badobe.com/demo/administrator/index.php?cid=3
Jun  2 08:50:53 localhost httpd: HTTP_COOKIE: PHPSESSID=feg3ecd4rsefvd03mgg6qear21
Jun  2 08:50:53 localhost httpd: Cookie: PHPSESSID=feg3ecd4rsefvd03mgg6qear21
Jun  2 08:50:53 localhost httpd: HTTP_CONNECTION: keep-alive
Jun  2 08:50:53 localhost httpd: Connection: keep-alive
Jun  2 08:50:53 localhost httpd: HTTP_IF_MODIFIED_SINCE: Sun, 02 Jun 2013 15:48:42 GMT
Jun  2 08:50:53 localhost httpd: If-Modified-Since: Sun, 02 Jun 2013 15:48:42 GMT
Jun  2 08:50:53 localhost httpd: HTTP_CACHE_CONTROL: max-age=0
Jun  2 08:50:53 localhost httpd: Cache-Control: max-age=0

score 7 · Answer 1 · answered Jun 02 '13 at 16:00

7

Because apache_request_headers() returns an associative array of all the HTTP headers in the current request, where as $_SERVER gives more than that

header details
path details
script locations

answered Jun 02 '13 at 16:00

Starx

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Thanks Starx. Is there anything different or new in `apache_request_headers()` which isn't in `$_SERVER`? – user1032531 Jun 02 '13 at 16:01
Thanks again Starx. But isn't `apache_request_headers()` redundant? See my edited original post. What new information does it provide? Also, is it microscopically slower than just accessing the $_SERVER array? – user1032531 Jun 02 '13 at 16:12

score 6 · Accepted Answer · answered Jun 02 '13 at 16:06

6

i would guess the function only works with Apache. but that is just a wild guess

furthermore i would guess the function returns ALL headers, where I think $_SERVER contains a predefined set of headers

answered Jun 02 '13 at 16:06

nl-x

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score 5 · Answer 3 · answered Jun 23 '15 at 14:14

apache_request_headers is not (completely) portable, and $_SERVER is not entirely complete. Most specifically $_SERVER never contains any Authorization header, no matter if PHP could process its value internally or not.

Since 5.4.0 apache_request_headers was patched to also show all headers in CGI deployments.

apache_request_headers() versus $_SERVER

3 Answers3

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