Question

The first loop gets the 2 values for hostkarma just fine. The 2nd loop fails for accredit.habeas and I get “Invalid argument supplied for foreach() on line 11”. Where am I going wroge with the “foreach($value as $val)” loop?

$hosts = array('209.49.180.233','209.49.180.234');
foreach ($hosts as $host)                    // Loop for IP addresses
{
    $rbls = array('hostkarma.junkemailfilter.com','accredit.habeas.com');
    foreach ($rbls as $rbl)                  // Loop for domains
    {
        $hostname = gethostbyaddr( $host );
        $lookup = $hostname . '.' . $rbl;
        $value = gethostbynamel($lookup);
    foreach($value as $val)                  // loop for multiple record/code values
            {
                echo $host, $rbl, $val . "
";
            }
    }
}

Answer 1

You must add:

if (is_array($value))

just before foreach($value as $val) line.

For the cases when gethostbynamel is failing its return value $value is not an array hence causing Invalid argument supplied for foreach() error.