Script to create htaccess file for simple auth, but also allow FB crawler in by IP address

create_htaccess_allow_fb.php

# Creates an .htaccess file that sets up simple auth (use SSL only!) but allows FB IP address through
# FB indicates its IP addresses shift often, so will need to be cronned 
# See https://developers.facebook.com/docs/sharing/webmasters/crawler
# MIT License https://opensource.org/licenses/MIT
# You need to create and update location of AuthUserFile, your php interpreter

#!/usr/bin/php
AuthType Basic
AuthName "Authentication Required"
AuthUserFile "/location/of/.htpasswd"

<RequireAny>
Require valid-user
<?php
$fb_ips=`whois -h whois.radb.net -- '-i origin AS32934' | grep ^route`;
$fb_ips = str_replace ("route6:", "require ip ", $fb_ips);
$fb_ips = str_replace ("route:", "require ip ", $fb_ips);
echo $fb_ips;
?>
</RequireAny>