Several sites on single WordPress installation

development, ideas, php, wordpress 3 Comments »

I have a couple of other WordPress blogs on the same server besides this one. One day I realised that all of them have 3 different WP versions and, as result, different admin areas which is not handy. I decided to make them use the same WordPress installation.

Ok, first of all, I deleted wp-admin and wp-includes folders and created new ones as symbolic links. Though the frontend worked well, I couldn’t log in into admin area, because the browser was redirected to that blog which was the base for all the rest for unknown reason.

The investigation shown, that admin area of WordPress is a separate sub-application, thing in itself, and in my case it resolves the absolute path to its source as the path to the base blog. I wanted each blog to use its own folder because there are config file and uploads folder.

It took me some time to find a solution. It requires two steps.

First, I added this line to the top of the .htaccess to make any PHP request to the blog (the blog front-end and the admin area scripts) call the same script before thier start:

#fix for several sites on the same WP installation
php_value auto_prepend_file "/var/www/site_doc_root/prepend.php"

In this code /var/www/ is the root folder for all my sites, and the site_doc_root is the document root of the current site (folder where all its files are located).

OK, the 2nd step — the contents of the prepend.php script. It is easy — it just must define an absolute path constant which is used all around the WordPress:

<?php
define('ABSPATH', dirname(__FILE__).'/');

OK, after that I decided not to use one of the blogs as source for others, but download a fresh copy of WordPress and make it a source of the symbolic links for all my blogs. This helps to update them.

Then I deleted wp-admin and wp-includes folders and some wp-files and recreated them as symlinks. Attention to wp-config.php — don’t delete it, keep it unique for every site!

To make this task easier, I created setup.sh file, pasted the contents I show below, run this command

chmod 755 setup.sh

then I copied it in every site folder and launched there for every site:


ln -s /var/www/wordpress/wp-admin wp-admin
ln -s /var/www/wordpress/wp-includes wp-includes

ln -s /var/www/wordpress/wp-app.php wp-app.php
ln -s /var/www/wordpress/wp-atom.php wp-atom.php
ln -s /var/www/wordpress/wp-blog-header.php wp-blog-header.php
ln -s /var/www/wordpress/wp-comments-post.php wp-comments-post.php
ln -s /var/www/wordpress/wp-commentsrss2.php wp-commentsrss2.php
ln -s /var/www/wordpress/wp-config-sample.php wp-config-sample.php
ln -s /var/www/wordpress/wp-cron.php wp-cron.php
ln -s /var/www/wordpress/wp-feed.php wp-feed.php
ln -s /var/www/wordpress/wp-links-opml.php wp-links-opml.php
ln -s /var/www/wordpress/wp-load.php wp-load.php
ln -s /var/www/wordpress/wp-login.php wp-login.php
ln -s /var/www/wordpress/wp-mail.php wp-mail.php
ln -s /var/www/wordpress/wp-pass.php wp-pass.php
ln -s /var/www/wordpress/wp-rdf.php wp-rdf.php
ln -s /var/www/wordpress/wp-register.php wp-register.php
ln -s /var/www/wordpress/wp-rss.php wp-rss.php
ln -s /var/www/wordpress/wp-rss2.php wp-rss2.php
ln -s /var/www/wordpress/wp-settings.php wp-settings.php
ln -s /var/www/wordpress/wp-trackback.php wp-trackback.php
ln -s /var/www/wordpress/xmlrpc.php xmlrpc.php

That’s not all ;)

I decided to update my WordPress installation every one or two months.

To do that, in the /var/www/ folder (where all my sites reside) let’s create an update script update_wordpress.sh with the following contents:

wget --timestamping http://wordpress.org/latest.zip
unzip -o latest.zip

This will download a fresh copy of the wordpress if it’s changed (though wordpress team doesn’t show the file Last-Modified header, I think one day they will) and unzip it to /var/www/wordpress/ folder which is the source for our symlinks.

Yes, you got it right — launching this script is all I need to update all my blogs.

Let’s make it periodic:

crontab -e

and then add this line to run the update process automatically every 1st day of every month at 9 AM:

0 9 1 * * /var/www/update_wordpress.sh > mail -s "Wordpress updated" your@email.com

P.S. Of course, SVN checkout can be used for that purpose :)

RSS feed of error log

development, ideas, php No Comments »

Your PHP application logs every error to error log. Do you want to keep track of them in your favourite Feed Reader? Then follow up reading this article!

First of all, you must tell to your application to log errors to a log file. Two parameters must be set: what to log and where to save it. First can be done by error_reporting setting, second — by setting error_log PHP value:

error_reporting( E_ALL & ~E_NOTICE ); //all except notices
ini_set( 'error_log', 'temp/error.log' );

Put it in the beginning of your application, for example, at the top of index.php file.

By the way, you can write something custom in the error log by calling error_log function:

error_log('something');

OK, now, how to make a feed from your error log.

You can do this in a few ways.

First, let’s do it manually.

Manual solution

1. Remove ini_set setting described above. Then create .htaccess file in the top folder of your application and place this line in it:

php_value error_log temp/error.log

It will tell to all scripts of your application to take this setting into consideration without manual calling of ini_set function.

2. Create feed.php file. Place this line inside it:

$contents = file_get_contents( ini_get( 'error_log' ) );
echo nl2br( $contents );

It’s dirty for now, but enough as a check.

3. Make sure that your error log file is not empty. Now you can access your feed.php file via browser and check that it’s showing you the contents of your error log.

4. Now you should create an RSS feed from contents of the file. You can rely on your framework or use a custom solution, e.g. download EasyRSS class and fill the contents of the feed with data from the error log (you would need to think about regexp to parse date and error text from it).

After that you could feed your feed reader with the feed address ;]

Ready-made solution

Download a ready PHP class that will do all it for you — RSS Feed. Yes, it’s simple. You can even protect your feed with a password.

Notes:

  • on the production server change your error_reporting value, for example, to log fatal errors only.
  • log errors in the catch() part of the exception handling mechanism:
    try{ ... }
    catch(Exception $e) {
      error_log( $e->getMessage() );
    }

Using PHPClasses.org for marketing purposes

ideas, marketing, php, php classes 2 Comments »

Once upon a time I took a look at my Google Analytics account and found out that phpclasses.org is 5th source medium for two my blogs (this one and my russian blog).

I have 8 classes submitted. Calculation shows that 7% of my blogs visitors are my classes downloaders and viewers for all the time my classes and blogs exist, and 11% – for last week.

Take into account, that

  • I get these people to me without any move – I have just placed the links once.
  • in-bound links improve Google PageRank
  • count of links is limited only by your imagination ;]

To check that all my classes have all needed links in “Related links” section, I wrote a PHP script that adds a link if it’s not present on your class page. It was written fast so there not so much error checks; to use it, just

  1. type your login/pass,
  2. list IDs of your classes and
  3. define the list of links to be placed in “Related links” section of every class page.

Script supports more than one login/pass pair. If such link is already present, it will be skipped. CURL is required for your PHP server.

You can download it and use for free.

Do you need a handwriting generating service?

ideas 6 Comments »

Now, my reader, I need your feedback: do you think it’s a good idea to create a handwriting generation service?

The idea is you come to a site, type some text in a form and as result download a PDF file which being printed looks exactly as if you wrote by a black gel ink pen.

I’m sure I can do this since I was working on such stand-alone tool several years ago. It would be fun for me to reimplement it for on-line use, but is there any point in such service?

What do you think?

P.S. It’s not a font looking like a hand-writing. You won’t recognize that it was generated+printed if an ink printer is used. As example:

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