(PHP 4, PHP 5)
ip2long -- Converts a string containing an (IPv4) Internet Protocol dotted address into a proper addressThe 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.
Note: As of PHP 5.0.0 ip2long() returns FALSE when ip_address is invalid.
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 both PHP 4 and PHP 5:
ip2long() should not be used as the sole form of IP validation. Combine it with long2ip():
ip2long() will also work with non-complete IP addresses. 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 FALSE for the IP 255.255.255.255 in PHP 5 <= 5.0.2. It was fixed in PHP 5.0.3 where it returns -1 (same as PHP 4).