ip2long()

Anon

Whenever I try to use the ip2long() function, I get back a negative number. Whenever I use bindec() to convert a binary number to decimal, I get back a negative number as well. Is there someting wrong with my config, or am I not using these functions correctly?

Taken straight from the manual (http://php.net/manual/function.ip2long.php):
<?php
$ip = gethostbyname("www.php.net");
$out = "The following URLs are equivalent:<br>\n";
$out .= "http://www.php.net/, http://".$ip."/, and http://".ip2long($ip)."/<br>\n";
echo $out;
?>

The result for me is this: http://nemesis2.com/testdir/ip2long.php

I am using php-4.0.3pl1. Can anyone else verify that this function works or does not work for them?

Thanks,
Jason

Anon

The following URLs are equivalent:
http://www.php.net/, http://208.247.106.187/, and http://-789091653/
4.0.3pl1

Anon

Did a search on the bugs page, came up with this:
http://bugs.php.net/bugs.php?id=7248

According to php.net: "It is meant to do so[return a negative number], PHP long values are signed."

What does that mean? How do I get the actual number I want?

Anon

dunno, i've never used the function before

just pasted the output of what appeared from your code running on my webserver.

debian linux (woody) kernel 2.2.17

apache 2.2

Anon

IP addresses are 32-bits, unsigned. If you have, for example, 255.0.0.0 as your IP address, in binary notation it looks like this:

11111111000000000000000000000000

The problem is that PHP uses 32-bit, unsigned integers. The leftmost bit in an unsigned int, if == 1, indicates a number is negative. That's fine unless you're trying to manipulate IPs using PHPs... the larger numbers wrap around and become negative.

It might help to do sprintf("%u",ip2long($whatever)). That will print the positive number you want.

Hope that helps,

Jason Signalness
Systems Administrator, BTINet.