ip2long
(PHP 4 )
ip2long -- Converts a string containing an (IPv4) Internet
Protocol dotted address into a proper address.
Description
int ip2long ( string ip_address)
The function ip2long() generates an IPv4 Internet network
address from its Internet standard format (dotted string)
representation. If ip_address is invalid then -1 is returned.
Note that -1 does not evaluate as FALSE in PHP. Example
1. ip2long() Example
<?php
$ip = gethostbyname("www.example.com");
$out = "The following URLs are equivalent:<br />\n";
$out .= "http://www.example.com/, http://" . $ip
. "/, and http://" . sprintf("%u", ip2long($ip))
. "/<br />\n";
echo $out;
?>
Note: Because PHP's integer type is signed, and many IP
addresses will result in negative integers, you need to
use the "%u" formatter of sprintf() or printf()
to get the string representation of the unsigned IP address.
This second example shows how to print a converted address
with the printf() function : Example 2. Displaying an IP
address
<?php
$ip = gethostbyname("www.example.com");
$long = ip2long($ip);
if ($long === -1) {
echo "Invalid IP, please try again";
} else {
echo $ip . "\n"; // 192.0.34.166
echo $long . "\n"; // -1073732954
printf("%u\n", ip2long($ip)); // 3221234342
}
?>
ip2long() will also work with non-complete ip adresses.
Read http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/libs/commtrf2/inet_addr.htm
for more info.
Note: ip2long() will return -1 for the ip 255.255.255.255
See also long2ip() and sprintf().
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