inet_ntop

(PHP 5 >= 5.1.0RC1)

inet_ntop --  Converts a packed internet address to a human readable representation

Description

string inet_ntop ( string in_addr )

This function converts a 32bit IPv4, or 128bit IPv6 address (if PHP was built with IPv6 support enabled) into an address family appropriate string representation. Returns FALSE on failure.

例子 1. inet_ntop() Example

<?php
$packed
= chr(127) . chr(0) . chr(0) . chr(1);
$expanded = inet_ntop($packed);

/* Outputs: 127.0.0.1 */
echo $expanded;

$packed = str_repeat(chr(0), 15) . chr(1);
$expanded = inet_ntop($packed);

/* Outputs: ::1 */
echo $expanded;
?>

注: 本函数未在 Windows 平台下实现。

See also long2ip(), inet_pton(), and ip2long().


add a note add a note User Contributed Notes
MagicalTux at FF dot st
04-May-2005 07:43
For people who need this function but don't have it, I could write a function which should give almost the same result.

<?php
function my_inet_ntop($ip) {
   if (
strlen($ip)==4) {
      
// ipv4
      
list(,$ip)=unpack('N',$ip);
      
$ip=long2ip($ip);
   } elseif(
strlen($ip)==16) {
      
// ipv6
      
$ip=bin2hex($ip);
      
$ip=substr(chunk_split($ip,4,':'),0,-1);
      
$ip=explode(':',$ip);
      
$res='';
       foreach(
$ip as $seg) {
           while(
$seg{0}=='0') $seg=substr($seg,1);
           if (
$seg!='') {
              
$res.=($res==''?'':':').$seg;
           } else {
               if (
strpos($res,'::')===false) {
                   if (
substr($res,-1)==':') continue;
                  
$res.=':';
                   continue;
               }
              
$res.=($res==''?'':':').'0';
           }
       }
      
$ip=$res;
   }
   return
$ip;
}
?>

I followed IPv6 reprenstation rules :
- A series of "0"s in a 16bit block can by represented by "0".
- A series of blocks containing only "0"s can be suppressed and represented by "::" (this can be done only once)

(source : http://www.ipv6style.jp/en/faq/latest.shtml#2003022112 )

Example:
<?php
$packed
= str_repeat(chr(0), 15) . chr(1);
$expanded = my_inet_ntop($packed);

/* Outputs: ::1 */
echo $expanded;
?>

I checked in CVS (2005-04-25) and didn't find the inet_ntop function (I really needed to handle IPv6) so I implemented it myself !
mirko dot steiner at slashdevslashnull dot de
24-Mar-2005 03:08
i've used this nice one oneline code:

<?PHP
$one   
= 192;
$two    = 168;
$three    = 1;
$four    = 1;
                          
$ip = $one*pow(256,3) + $two*pow(256,2) + $three*pow(256,1) + $four*pow(256,0);
                          
echo
$ip;
?>

you can also put the first one, shift them by 24 bits to the right, take the secod and shift them by 16, the 3rd by 8 and put thouse all together bitwise...