CFLib.org – Common Function Library Project

Description:
IP4R Takes a common IP address (like 192.168.0.1) and converts it to it's IP4r equivalent. (in this case, it'd be 1.0.168.192) This is used by mack DNS based black lists, and mail server software to check DNS based black lists.

Return Values:
Returns a string.

Example:

<cfscript>
 variables.ip_to_convert = '192.168.0.1';
 writeoutput("The IP4r of " & variables.ip_to_convert & " is " & ip4r(variables.ip_to_convert));
</cfscript>

Parameters:

Full UDF Source:

/**
 * IP4r converts standard dotted IP addresses to their reversed IP4r equivalent.
 * 
 * @param ip4      IP address. (Required)
 * @return Returns a string. 
 * @author Scott Glassbrook (cflib@vox.phydiux.com) 
 * @version 2, November 18, 2004 
 */
function ip4r(ip4) {
    return ReReplaceNoCase(ip4,  "([0-9]{1,3}).([0-9]{1,3}).([0-9]{1,3}).([0-9]{1,3})",  "\4.\3.\2.\1");
}