I used the following charset: $_=+(); As you can see only 7 chars. In the end the function log will be created,because this won't exceed the memory limit. In the beginning I created the php function assert and it was 99 mb large php file, way too big to get executed.

He uses a few tricks to get the language to create strings (counting to infinity), changing the letters in the resulting string, He includes the steps in the process and a large block of the non-alpha PHP code at the end of the post, a 46KByte block that echoes "log(12)".

I started to try and break the 10 charset limit of PHP non-alpha after @InsertScript showed me that PHP Dev supports [] syntax for arrays. I wondered if it would be possible to break the limit within production PHP. At first I thought you could but then after some testing I found that there was no way to concat without "." and no way to call a string as a function without $ and =. However since I got into PHP Non-alpha again I thought why not try and improve it and make the code tweetable.

He works through the whole process of his discovery - starting with the creation of a non-alpha version of "0" (zero), moving into letter creation and finally all the way up to a full word..."assert". The result is tweetable code that echoes that string and contains more symbols than letters. If you're interested in more of this non-alpha kind of coding, check out some of the other posts on his blog.

My first post on PHP non-alpha numeric code was a bit brief, in the excitement of the discovery I failed to detail in depth the process. I've decided to follow up with a tutorial and hopefully explain the process better for anyone wanting to learn or improve the technique. The basis of PHP non-alphanumeric code is to take advantage of the fact that PHP automatically converts Arrays into a string "Array" when using in a string context.

He includes some basic examples showing how, with just a combination of things like "+", "_" and "[" or "]" you can reproduce similar output to echoing out an array and use that "Array" output string to get to other strings (like the letter "B"). There's also a more lengthy example showing how to build up the string "print 1+1" and have it execute using this technique.