inet_ntop()

(PHP 5 >= 5.1.0, PHP 7)

Converts a packed internet address to a human readable representation

说明inet_ntop(string$in_addr):string

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.

参数$in_addrA 32bit IPv4, or 128bit IPv6 address.

返回值

Returns a string representation of the address 或者在失败时返回FALSE.

范例

Example #1inet_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;

?>

更新日志版本说明5.3.0This function is now available on Windows platforms.

参见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 addressPHP'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.For people who need this function but don't have it, I could write a function which should give almost the same result.

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:

$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 !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] )

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