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.
In PHP 5 ip2long() returns FALSE
when the ip_address is in valid.
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 in PHP 4:
Example 2. Displaying an IP address (PHP 4) |
<?php
$ip = gethostbyname("www.example.com");
$long = ip2long($ip);
if ($long === -1) {
echo "Invalid IP, please try again";
} else {
echo $ip . "\n"; echo $long . "\n"; printf("%u\n", ip2long($ip)); }
?>
|
|
This third example shows how to print a converted address with the
printf() function in PHP 5:
Example 3. Displaying an IP address (PHP 5) |
<?php
$ip = gethostbyname("www.example.com");
$long = ip2long($ip);
if ($long === false) {
echo "Invalid IP, please try again";
} else {
echo $ip . "\n"; echo $long . "\n"; printf("%u\n", ip2long($ip)); }
?>
|
|
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().
