Grr. credit card masking script

one too many XXXXs

[lorax]

The following code is designed to take a string like this: "Card number: 1111222233334444" and convert it into this: "Card number: XXXX-XXXX-XXXX-4444" and send it along in an email to the Admin of the cart.

The problem is the actual string it's sending back is this: "Card number: XXXX-XXXX-XXXX-XXXX-4444" I can't find the bugger that's causing the extra set of Xs!

Note: the function func_get_modified_details is what starts the process off. $details is passed from a script that calls this function.

function func_expand_string ($s, $count = 4) {
 $s = preg_replace("/ /","", $s) ;
 if(!$s) return "" ;
 if(!is_numeric($count) ¦¦ $count <= 0 ) $count = 4 ;
 $arr = preg_split("//",$s, -1, PREG_SPLIT_NO_EMPTY) ;
 if($arr && is_array($arr)) {
 $tmp = array() ;
 $i = 0 ;
 foreach($arr as $k=>$v) {
 $tmp[$i] .= $v ;
 if((($k+1)%$count) == 0 )
 $i++ ;
 }
 }
 $return = implode("-", $tmp) ;
 return $return ;
}
#
# Credit Card Mask -> XXXX XXXX XXXX 0000
#
function func_get_modified_details ($details) {
 preg_match_all("/\\nCard number: (.*)\\n/",$details,$cc) ;
 $cc = substr_replace($cc[1][0],str_repeat("X",strlen($cc[1][0])),0, strlen($cc[1][0])-4);
 $cc = func_expand_string ($cc) ;
 $return = preg_replace("/\\nCard number: (.*)\\n/","\nCard number: ".$cc."\n",$details) ;
 return $return ;
}

[coopster]

You are repeating "X" 16 times, lorax. So it is "squeezing" in an additional 4 X's ;-)

$cc = substr_replace($cc[1][0],str_repeat("X",strlen($cc[1][0])-4),0, strlen($cc[1][0])-4); 

[lorax]

Thanks coop. I knew it had to be simple. I just could see it!

[coopster]

You betcha.

I created a similar function once for something else so I took that and modified it a bit to show you another path you could use in your implementation. Take or leave it, but here is another example (note: only works in PHP5 because of the str_split function):

function maskCC($n, $b = 4, $p = 16, $m = 'X', $l = 4) 
{ 
 // $n = 'Card number: 1234567890123456' string 
 // $b = break into how many in each chunk? 
 // $p = pad to what length? 
 // $m = mask character? 
 // $l = leave how many numbers showing? 
 preg_match [php.net]("/Card number:\s*(\d+)[^\d]*/i", trim($n), $matches); 
 $pattern   = "/Card number:\s*(\d+)/ie"; 
 $replacement = " 
  implode [php.net]('-',  
   str_split [php.net]( 
    substr_replace [php.net]( 
     str_pad [php.net]('$1', '$p', '0', STR_PAD_LEFT),  
     str_repeat [php.net]('$m', $p-$l),  
     0,  
     $l * -1 
    ),  
   $b) 
  ); 
 "; 
 return preg_replace [php.net]($pattern, $replacement, trim($n)); 
} 
var_dump(maskCC("\nCard number: 1222233334444\n"));

I suppose you could modify it to meet your needs though (replace that str_split function with your own user-defined function for now) if you felt up to it. Anyway, thought I'd throw down another idea for you ...

[henry0]

I knew yesterday that it was a good idea to flag that thread.

Just shamelessly copied the function!

Thanks

Cheers :)
Henry

[vincevincevince]

Try this :)

$cardno="Card number: 1234567891123456";
print "Card number: XXXX-XXXX-XXXX-".substr($cardno,-4);

[jatar_k]

I'm with you vincevincevince,

why play around so much when you can just ripoff the last 4 digits and stick them onto a string

[coopster]

I would agree, but in the instance that I first created the function shown I had to return formats differently each time (not for credit card numbers). You can't just rip off the last few digits anymore. That's where the function came in handy.

var_dump(maskCC("\nCard number: 1222233334444\n")); 
// XXXX-XXXX-XXXX-4444 
var_dump(maskCC("\nCard number: 111122223333444455\n",4,18,'#',5)); 
// ####-####-####-#444-55 
var_dump(maskCC("\nCard number: 11122233\n",5,12,'*',6)); 
// *****-*1222-33