MACROMEDIA COLDFUSION 5-DEVELOPING, Develop Manual

Page: 284 / 438

264 Chapter 14 Using Regular Expressions in Functions
An excellent reference on regular expressions is Mastering Regular Expressions,
Jeffrey E. F. Friedl. O’Reilly & Associates, Inc., 1997. ISBN: 1-56592-257-3, http://
www.oreilly.com.
Limiting input string size
In CFML regular expression functions, large input strings (greater than
approximately 20,000 characters) cause a debug assertion failure and a regular
expression error occurs. To avoid this, break your input into smaller chunks, as the
following example shows. Here the variable input has a size greater than 50000.
<cfset test = mid(input, 1, 20000)>
<cfset out1 = REReplace(test, "[
#Chr(9)##Chr(13)##Chr(10)#]+#Chr(13)##Chr(10)#", "#chr(10)#",
"ALL")>
<cfset test = mid(input, 20001, 20000)>
<cfset out2 = REReplace(test, "[
#Chr(9)##Chr(13)##Chr(10)#]+#Chr(13)##Chr(10)#", "#chr(10)#",
"ALL")>
<cfset test = mid(input, 40001, len(input) - 40000)>
<cfset out3 = REReplace(test, "[
#Chr(9)##Chr(13)##Chr(10)#]+#Chr(13)##Chr(10)#", "#chr(10)#",
"ALL")>
<cfset result = out1 & out2 & out3>
Anchoring a regular expression to a string
You can anchor all or part of a regular expression to either the beginning or end of
the string being searched:
•
If the caret (^) is at the beginning of a (sub)expression, the matched string must
be at the beginning of the string being searched.
•
If the dollar sign ($) is at the end of a (sub)expression, the matched string must be
at the end of the string being searched.