Programming ColdFusion MX, 2nd Edition

Useful Regular Expressions

Now that you have a better idea of how regular expressions work, let’s take a look at how you can actually use them in your own ColdFusion applications. Here are some regular expressions that perform common search-and-replace tasks:

• Replace all characters in a string that aren’t numbers, letters, or underscores with an underscore:

  <cfset NewString = REReplaceNoCase("This is a test", "\W", "_", 
         "All")>

• Replace all spaces in a filename with the underscore character; this is useful in situations where you allow users to upload files to your ColdFusion server via their web browsers:

  <cfset NewFilename = REReplace("My File Name.txt", " ", "_", "All")>

• Return the full directory path from a string containing a full path including filename:

  <cfset TheDirectory = REReplaceNoCase(MyPath, "\w+\.\w+", "", "All")>

• Return the filename from a string containing a full path including filename:

  <cfset TheFileName = REReplaceNoCase(MyPath, "([A-Z]:\\)|\w+\\+", "", "All")>

• Remove all doubled words in a string:

  <cfset NoRepeats = REReplaceNoCase("I want to to go to the park.", 
    "\b([a-z]+)[ ]+\1","\1","All")>

• Strip all HTML tags from a string; this is useful for removing HTML from form-field submissions:

  <cfset NoHTML = REReplace(MyString, "<[^>]*>", "", "All")>

• Remove all HTML anchors in a string, leaving just the text, if any:

  <cfset NoHTMLLinks = 
    REReplaceNoCase(MyString, "<a [^>]*>([[:print:]]*)</a>","\1",'All')>

• Format all email addresses in a string as HTML mailto: links. Note ...