The lua quiz has changed! We have replaced lua questions with answers! And from those answers you'll find further links to even more information - forums where you can ask questions, training courses, longer articles, and more. [link to quiz index] ... If you really want the old quiz questions, you can find them here, here, here and here ... and with onward links to the possible answers to each question too.

Handling nasty characters - Perl, PHP, Python, Tcl, Lua

Are your writing or maintaining a web based application that uses forms? If so, you have better be aware of some of the nasty characters that are around! The < character, when echoed back from a ...

Learning PHP, Ruby, Lua and Python - upcoming courses

The following programming courses are all booking well, but still have good availability: PHP - starting 6th July Ruby - starting 14th July Lua - starting 10th August Python - starting 17th August ...

RT @brento - a valuable source for the twitter newbie

So I'm new(ish) on Twitter ... what do those @ symbols and things like RT and OT mean? Brent Ozar explains in his blog, and also tells us why people follow and why people don't follow. OK - I'm ...

Learning to program in PHP, Python, Java or Lua ...

... or in Ruby, Tcl, C, C++ or Perl Are you new to computer programming? Is it so long since you programmed that you feel very rusty and would like to start again from basics? If you've said "yes" to ...

Lua - IAQ (Infrequently Answered Questions)

Here are a handful of "one line" answers from the end of the Lua Course I was running at the end of last week • Command line parameters in Lua are available to the program in an indexed table ...

Passing a table from Lua into C

In a previous article, I showed you a simple example of how you can call a function that's written in C from Lua, and a second example that extended that - passing simple parameters in to the C ...

Calling functions in C from your Lua script - a first HowTo

This short article shows you how to call a function that's written in C from a program written in Lua, how to write the function that's called, and how to turn it into an appropriate library and load ...

Lua Course, and the Wiltshire Countryside too

With courses such as Lua Programming, our delegates come from far and wide - it's very much a niche subject, and that's why we provide facilities that are a little different to most training ...

Formatting with a leading + / Lua and Perl

In formatted printing, you can often use a leading "+" in the format string to force a positive sign to be added in front of positive numbers - for example "%+4d" means an integer, to base 10, 4 ...

Lua examples, Lua Courses

Programming training is much more effective if the delegates are shown how a particular program is written, rather than just the final result ... show them just the final result and they'll ask "but ...

First class functions in Lua lead to powerful OO facilities

"In Lua, function names are first class variables." Ok - so what does that mean? At the most direct / simplest, it means that a function can be stored in a variable - so that you can write ...

Lua - Table elements v table as a whole

Lua ... If you refer to a table name WITHOUT square brackets, you are referring to (and will effect) the whole table ... but if you refer to a table name and put something thereafter in square ...

Clean code, jump free (Example in Lua)

The "goto" statement - in languages that still support it - is regarded with disdain by Computer Scientists as it makes for spaghetti code - hard to follow and going all over the place! In some ways, ...

Rules, suggestions, considerations for Lua variable names

Rules for naming variables in Lua ... * MUST start with a letter or underscore * which MUST be followed by as many or as few letters, digits, underscores as you like * Case sensitive (sound bite - ...

If you are learning Lua, here are some more examples

During some courses, I write few (if any) new examples in front of my delegates, rather relying on the standard ones in the training notes (which I wrote anyway!) and making small changes and ...

Sorting in lua - specifying your own sort routine

In Lua, the table.sort function allows you to sort a table and by default is sorts into the order that's given back by the < operator on each of the objects to be sorted. If you want to override ...

Saying NOT in Perl, PHP, Python, Lua ...

"Isn't there one standard way to say NOT?" asked one of my delegates on today's course - and it's an excellent question. But the answer to a question about a negative subject is itself in the negative ...

Lua Course - here is the index

If you want to look something up in a book, you'll probably use the index. And so it is in Lua that if you want to look something up in a table (the collection structure in Lua), you'll use an index ...

Towards Object Oriented Programming in Lua

I've spent a lot of the weekend working on our Lua course ... and for those of you new to this language I'll be sharing a few snippets with you here on "The Horse's Mouth" over coming weeks. Today, ...

Co-routines in Lua - co-operative processing

CoRoutines in Lua allow you to have a number of pieces of co-operative code which (whilst they’re not running in parallel in a true multithreaded way) allow you to progress through multiple strands ...

Short circuit evaluation (lazy operator) in Lua

In Lua, if a partial expression evaluates to true the following section will NOT be evaluated if it follows an or because the whole thing cannot be true. If a partial expression evaluates to false, ...

Lua - a powerful, up and coming scripting language

Lua is a powerful, lightweight scripting language. It combines simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics. It is ideal for ...

Training in Lua

I'm always keeping my ears and eyes open for up and coming languages, and earlier this week the subject of lua came up. Lua is a procedural programming language, written as long ago as 1993, which ...

Evaluating arithmetic expressions in configuration files

An interesting question came up in a consultants session this evening - how to take an expression that's held in a configuration file such as (A3+C3)*(A5+E6) and have the program work out the ...

Red Luas - early life and times

A little off-topic, but it's been suggested that I post this piece to save it "for posterity". Hmm - not sure that this website will be around in 20 years time let alone posterity, but here's my ...