Regular Expression: The Theory behind it!

When it comes to validating input regular expression becomes a very important part of your security plan.  On a side note ensure your regular expressions are doing Acceptance-List approach and not a Deny-List approach to validation as mentioned in a previous blog. 

Those use to writing a lot scripts have a very good understanding of regualar expressions and their are many others that find it challenging.  I have discovered a twelve parts blog by Eric Lippert of Microsoft on the theory behind regular expression.  For those that like to learn the theory behind regular expressions I highly recommend reading this.  For those learning regular expression it may help to under the theory behind what you are learning.

• Regular Expression from Scratch, Part One: Defining Terms
• Regular Expression from Scratch, Part Two: Some Examples of Languages
• Regular Expression from Sratch, Part Three: Concatenation
• Regular Expression from Sratch, Part Four: The Kleene Closer of a Language
• Regular Expression from Sratch, Part Five: The Regular Expression Language
• Regular Expression from Sratch, Part Six: The Insanely Clever Bit
• Regular Expression from Sratch, Part Seven:  Listing all Members of a Language in Order
• Regular Expression from Sratch, Part Eight: The Diagonal Argument
• Regular Expression from Sratch, Part Nine: A Dream of a Machine
• Regular Expression from Sratch, Part Ten: Magic
• Regular Expression from Sratch, Part Eleven: Eliminating Multi-Symbol Rules
• Regular Expression from Sratch, Part Twelve: Superpositions of States

Comments

• Anonymous
  June 16, 2009
  PingBack from http://topalternativedating.info/story.php?id=14094