choose.php - ChooSE your search engine

choose.php is a PHP script intended to let users choose their favorite search engine. Instead of providing a link to a particular web search one can point to an installation of choose.php which allows users to choose a preferred search engine before doing the actual search.

The script is meant to be used for instance in blog posts and comments¹ or in electronic mail communication (for this purpose the script produces a link to itself to be copied into the message).

The basic idea is that people should have a free and easy to use choice of search engines.

ChooSE @wox.at

• https://wox.at/s/

Features

• Freedom of choice ;-)
• Extended listing of search engines: Shown with ?ext added to URL (example showing extended list)
• Preselect a search engine: A default search engine is set up by the script itself. It can be overruled by adding ?e= + the key for the search engine (example for Startpage).²
• Search engines can be easily added or changed by editing the script.
• Access keys for search engines: E.g. Alt-Shift-g for Google, Alt-Shift-b for Bing, ...
• Access keys for search string field (Alt-Shift-f) and Submit (Alt-Shift-s)

Instructions for use

Feel free to use my own installation of choose.php at https://wox.at/s/. However, I recommend that people set up their own search engine switcher (for added freedom of choice and privacy).

Basically, choose.php comes as a single PHP file. Download it (see links below), rename appropriately, set permissions if needed, and edit the file to change a few settings. That's it.

Important settings to make it work are values of $me, $mesuffix, and $c_action. Let's assume you have a blog at http://blog.rats.at. You copied choose.php to the main directory, so it should be available at http://blog.rats.at/choose.php. Then set

$me='http://blog.rats.at/choose.php';
$mesuffix='?q=';
$c_action="$me";

URL rewriting

For https://wox.at/s, I use URL rewriting (on an Apache server) to remove the filename from the URL. I copied choose.php as index.php into the folder /s. My .htaccess contains

RewriteEngine   on
RewriteBase /s

RewriteRule ^$                        index.php  [L]

RewriteCond %{REQUEST_FILENAME}       !-f
RewriteCond %{REQUEST_FILENAME}       !-d
RewriteRule (.*)                      index.php?q=$1  [QSA,L]

With these rewriting rules I can set in index.php (i.e. choose.php)

$me='https://wox.at/s';
$mesuffix='';
$c_action="$me/";

Dealing with slashes

If you use the rewriting rules as shown above you'll probably observe that when searching for a string with 2 or more slashes (//) the Apache server will reduce the slashes to single slashes³.

A solution is to use RewriteCond %{THE_REQUEST} and %1 as in

RewriteEngine   on
RewriteBase /s

RewriteRule ^$                        index.php  [L]

RewriteCond %{REQUEST_FILENAME}       !-f
RewriteCond %{REQUEST_FILENAME}       !-d
RewriteCond %{THE_REQUEST}            ^GET\ /s/([^\s]+)
RewriteRule .                         index.php?q=%1  [QSA,L]

Speaking of slashes, in rare cases they are encoded as %2F instead of %252F. Apache by default does not accept %2F and returns a 404. One could probably write a RewriteRule for this, but another approach is to turn AllowEncodedSlashes on. However, this needs to be done in the server configuration:

# Needed for ChooSE but should not hurt otherwise either AllowEncodedSlashes On

Processing ? and & parameters

Eventually, we also want to pass ?ext and possibly other parameters to the script. For this we need another rule which needs to be inserted right after RewriteRule ^$ index.php [L]:

RewriteCond %{REQUEST_FILENAME}       !-f
RewriteCond %{REQUEST_FILENAME}       !-d
RewriteCond %{THE_REQUEST}            ^GET\ /s/(.*)\?(.*)\ HTTP/
RewriteRule .                         index.php?q=%1&%2  [QSA,L]

Download & source

• Download current version⁴: choose.php.txt (~ 14 KB; rename to e.g. choose.php)
  • Example CSS choose.css (~ 1 KB; should give reasonable results out of the box)
  • Example XML for search engine addon⁵: opensearch.xml (~ 1 KB; needs to be adapted, of course)
• View source (with syntax highlighting)