It is a common practice, to use ip2long() function for getting integer-representation of ip-address (for database-storage).
Problem:
on systems with 32-bit integers, ip2long() returns values from -2147483648 to 2147483647
on systems with 64-bit integers, ip2long() returns values from 0 to 42949672945
Which means, that if you were using INT as a storage type on 32-bit server, you will need to change that field to be UNSIGNED INT (or BIGINT) on 64-bit server.
There is no simple migration, sorry.
p.s. similiar problems can appear in other intger-related functions too
Actually, it is clearly shown in doc for ip2long that “you need to use the “%u” formatter of sprintf() or printf() to get the string representation of the unsigned IP address.”
I know. But signed long was just fine for me. I understand why it has changed.
The problem is: people tend to think about PHP as about high-level language (and hope, that it will take care of such interoperability issues).
But such examples show, that many parts of it are still low-levelish
I always use built-in Mysql function INET_ATON() and have no problems
Of course, the point is i never use other DB than Mysql
Which means, in fact, that PHP SHOULD deal with it by itself.
It’s not a pretty thing for language that supports :// wrappers to halt on this.