CFLib.org – Common Function Library Project

Description:
Performs a regex on the string and determines if it a valid IP address. The value passed must match contain four octets delimited by a period. Each octet must be a number from 1 to 255. The addresses 0.0.0.0 and 255.255.255.255 are not valid. Note This only checks the octet form of IP addresses. It does not check the binary form.

Return Values:
Returns a boolean.

Example:

<CFSET BADIP = "fred">
<CFSET BADIP2 = "120.120.120.0">
<CFSET IP = "216.115.108.245">
<CFOUTPUT>
Is #BADIP# valid? #IsIP(BADIP)#<BR>
Is #BADIP2# valid? #IsIP(BADIP2)#<BR>
Is #IP# valid? #IsIP(IP)#<BR>
</CFOUTPUT>

Parameters:

Full UDF Source:

/**
 * Returns TRUE if the string is a valid IP address.
 * 
 * @param string      String to be checked. 
 * @return Returns a boolean. 
 * @author Nathan Dintenfass (nathan@changemedia.com) 
 * @version 1, July 17, 2001 
 */
function isIP(ip){
    var ii = 1;
    //make sure it is a '.' delimited list 4 long
    if(listlen(ip,".") is not 4) return false;

    //make sure each item is a number between 1 and 255
    for(ii = 1;ii lte 4;ii = ii + 1){
        if(not isnumeric(listgetat(ip,ii,".")) OR listgetat(ip,ii,".") GT 255 OR listgetat(ip,ii,".") LT 0)    return false;
    }
    //check for the special cases of 255.255.255.255 or 0.0.0.0, which is not really valid
    if(ip is "255.255.255.255" OR IP is "0.0.0.0") return false;
    return true;
}