Convert IP to dottless decimal

[christa]

hi all

why this function return 0 and NOT 3573956936?

 

$ip = '213.6.65.72';
function ip2dec($ip) {
  $base=explode(".", $ip);
  $decimal=(double)$base[0]*16777216;
  $decimal+=$base[1]*65536;
  $decimal+=$base[2]*256;
  $decimal+=$base[3];
  if($decimal>2147483647) {
    $decimal-=4294967296;
  }
  return (int)$decimal;
}
echo ip2dec();

[Mchl]

ip2long

[PFMaBiSmAd]

And you've got to pass the function a value when you call it. 0 in = 0 out.

[christa]

ip2long

now, it returns:

-721010360

 

And you've got to pass the function a value when you call it. 0 in = 0 out.

how can i call my function to display the correct ip dottless?

[Mchl]

See Example #2 in the manual.

 

$ip = '213.6.65.72';
echo ip2dec($ip);

[nbarone]

And you've got to pass the function a value when you call it. 0 in = 0 out.

how can i call my function to display the correct ip dottless?

 

dotless? str_replace(".","",$ip);

however, what they said was if you do function(); it's the same as function(0); which in turn, 0 "mathed" against anything will return 0 (which is why you get 0!)

[christa]

however, what they said was if you do function(); it's the same as function(0); which in turn, 0 "mathed" against anything will return 0 (which is why you get 0!)

and so, how can i convert my ip into decimal value?

[nbarone]

by actually giving the function an IP...

 

last line of your code: echo $ip2dec();

should be: echo $ip2dec($ip);

[christa]

by actually giving the function an IP...

 

last line of your code: echo $ip2dec();

should be: echo $ip2dec($ip);

i tried but the result is:

-721010360

 

PS: i've seen the funtion on http://www.php.net/manual/en/function.gethostbyaddr.php#25373

[J.Daniels]

It is because of this part of the code:

 

if ($decimal > 2147483647) {
    $decimal -= 4294967296;
}

 

The number I get right before this is 3573956936

[Mchl]

$ip = '213.6.65.72';
printf("%u\n",ip2long($ip));

 

long integer is signed in PHP, you have to convert it to string to get unsigned value.