long2ip
(PHP 4, PHP 5)
long2ip — Converts an (IPv4) Internet network address into a string in Internet standard dotted format
Description
string long2ip
( string
$proper_address
)The function long2ip() generates an Internet address in dotted format (i.e.: aaa.bbb.ccc.ddd) from the proper address representation.
Parameters
-
proper_address -
A proper address representation.
Return Values
Returns the Internet IP address as a string.
See Also
- ip2long() - Converts a string containing an (IPv4) Internet Protocol dotted address into a proper address
- checkdnsrr
- closelog
- define_syslog_variables
- dns_check_record
- dns_get_mx
- dns_get_record
- fsockopen
- gethostbyaddr
- gethostbyname
- gethostbynamel
- gethostname
- getmxrr
- getprotobyname
- getprotobynumber
- getservbyname
- getservbyport
- header_register_callback
- header_remove
- header
- headers_list
- headers_sent
- http_response_code
- inet_ntop
- inet_pton
- ip2long
- long2ip
- openlog
- pfsockopen
- setcookie
- setrawcookie
- socket_get_status
- socket_set_blocking
- socket_set_timeout
- syslog
Коментарии
I wanted to be able to pass an IP address in a URL always as an unsigned int. I then converted it back as shown below:
$ip_addr = "192.168.100.25"; // example IP address that converts to neg #
$s32int = ip2long($ip_addr);
$us32str = sprintf("%u",$s32int); // convert to unsigned string
// display orig IP address, signed 32 bit version, unsigned 32 bit ver,
// finally converted back to IP addr
printf("%s ,%d, %s, %s", $ip_addr, $s32int, $us32str,
long2ip(-(4294967296-$us32str)));
// tested on Linux/Apache PHP 4.1.2
If the function doesn't exist:
<?
if (!function_exists("long2ip")) {
function long2ip($long) {
// Valid range: 0.0.0.0 -> 255.255.255.255
if ($long < 0 || $long > 4294967295) return false;
$ip = "";
for ($i=3;$i>=0;$i--) {
$ip .= (int)($long / pow(256,$i));
$long -= (int)($long / pow(256,$i))*pow(256,$i);
if ($i>0) $ip .= ".";
}
return $ip;
}
}
?>
If you're running a 32 bit machine you can get wrong IPs. To prevent from this just cast to float e.g.
<?php
long2Ip32bit($ip){
return long2ip((float)$ip);
}
?>
Use these two functions to convert from and to numbers compatible to MySQLs INET_ATON and INET_NTOA<?php
function convertIpToString($ip)
{
$long = 4294967295 - ($ip - 1);
return long2ip(-$long);
}
function convertIpToLong($ip)
{
return sprintf("%u", ip2long($ip));
}
?>
For a 32bit safe long2ip, which can accept string or signed integer input, try:
function safelong2ip($long) {
$binStr = sprintf("%032s", decbin((float)$long));
if (strlen($binStr) != 32) {
throw new Exception("Invalid IPv4 subnet!");
}
$ipArr = [];
for ($i = 0; $i < 4; ++$i) {
$ipArr[] = bindec(substr($binStr, $i*8, 8));
}
return implode('.', $ipArr);
}
an Anonymous wrote several years ago that you should cast the parameter to float to make sure that you get the right result on 32-bit machines. That probably never worked.
But the idea is on a good track: to convert a bitstring into an ip, use
$ip = long2ip((int)bindec($bits));
This works on 32- and 64-bit machines.