Programming ColdFusion

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(MyString, "[^0-9A-Z_]", "_", "All")>

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

  <CFSET NewFilename = REReplace(MyFileName, "( )", "_", "ALL")>

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

  <CFSET TheDirectory = 
    REReplaceNoCase(MyPath, "[A-Z0-9_]+\.[A-Z0-9_]+", "All")>

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

  <CFSET TheFileName = 
    REReplaceNoCase(MyPath, "([A-Z]:\\)|[A-Z0-9_]+\\+", "", "All")>

• Remove all doubled words in a string:

  <CFSET NoRepeates = REReplaceNoCase(MyString, "([A-Z]+)[ ]+\1","\1","All")>

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

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

• Remove all HTML from links in a string, leaving just the URL:

  <CFSET NoHTMLLinks = 
    REReplaceNoCase(MyString, "<a *href[^>]+>([^(</a>)]*)</a>","\1",'All')>

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

  <CFSET MailtoLinks = REReplace(MyString, ...