The inet_addr function converts a host address from a null-terminated string into a numeric value.
The system include file WinSock2.inc contains the following declaration for the inet_addr function:
function inet_addr(cp : address) : u_long; external dll='ws2_32.dll';
The only argument passed to the inet_addr function is the operating system address of the buffer containing the host address as a null-terminated string. You should use the the built-in function addr to get the operating system address of this buffer.
The inet_addr function returns an unsigned long value containing the host address represented as a numeric value, if the call is successful. If an error occurs then the value INADDR_NONE is returned.
The authoritative source of information about the WinSock2 library is the Microsoft Developers Network (MSDN). You can access the MSDN on the Microsoft website at msdn.microsoft.com.