inet_ntop

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

inet_ntopConverts a packed internet address to a human readable representation

Description

inet_ntop(string $ip): string|false

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.

Parameters

ip

A 32bit IPv4, or 128bit IPv6 address.

Return Values

Returns a string representation of the address or false on failure.

Examples

Example #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;
?>

See Also

  • long2ip() - Converts a long integer address into a string in (IPv4) Internet standard dotted format
  • ip2long() - Converts a string containing an (IPv4) Internet Protocol dotted address into a long integer
  • inet_pton() - Converts a human readable IP address to its packed in_addr representation

add a note add a note

User Contributed Notes 4 notes

up
35
ryansun81 at gmail dot com
14 years ago
For people who wondering what the meaning of this function name:
pton: a presentation(printable) format address to network address
ntop: a network address to presentation(printable) format address
up
3
marcus at synchromedia dot co dot uk
9 years ago
PHP's inet_ntop function is not compatible with the binary representation used by MySQL's INET6_ATON function, assuming you are using the recommended method of storing both IPv4 and IPv6 addresses in a VARBINARY(16) field. You need to convert it like this:

/**
* Convert a MySQL binary v4 (4-byte) or v6 (16-byte) IP address to a printable string.
* @param string $ip A binary string containing an IP address, as returned from MySQL's INET6_ATON function
* @return string Empty if not valid.
*/
function inet6_ntop($ip) {
    $l = strlen($ip);
    if ($l == 4 or $l == 16) {
        return inet_ntop(pack('A' . $l, $ip));
    }
    return '';
}

You don't need a function going the other way because MySQL's INET6_NTOA is already compatible with PHP's inet_pton function.
up
1
MagicalTux at FF dot st
19 years ago
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 !
up
-6
PandoraBox2007 at gmail dot com
13 years ago
Before inet_pton nice work
//2001:0db8:85a3:0000:0000:8a2e:0370:7334

After
//2001:db8:85a3::8a2e:370:7334

no need compare compress data
string inet_ntop ( string $in_addr [, bool $compress = false] )

---
To Top