Programming ColdFusion

Chapter 17. Regular Expressions in ColdFusion

Anyone who has ever worked with regular expressions knows what an indispensable tool they can be for parsing and manipulating text. Without them, text-processing operations such as search and replace can be very difficult to say the least. Those with experience in Unix-based languages such as Perl, awk, or Tcl are probably already familiar with regular expressions as they are used extensively in those languages. For those new to the world of regular expressions, don’t worry. This chapter shows you everything you need to know to start using regular expressions in your ColdFusion applications.

ColdFusion provides you with two sets of ColdFusion functions for finding and replacing strings. REFind( ) and REFindNoCase( )search for strings within blocks of text, while REReplace( ) and REReplaceNoCase( )perform search and replace operations. Both sets of functions are extremely powerful and allow you to add a whole host of useful text-manipulation features to your ColdFusion applications.

Before we get into the mechanics of regular expressions, it is important for you to gain a basic understanding of the regular expression language and how it is used by ColdFusion.

Regular-Expression Syntax

In their most basic form, regular expressions match characters on a one-for-one basis. Thus, you can match the first occurrence of the letter “a” in a search string as follows:

REFind("abcdefg", "a")

Likewise, you can search for the letters “can” in ...