The htonl function converts a value of type u_long from host to TCP/IP network byte order (which is big-endian).
The system include file WinSock2.inc contains the following declarations for the u_long type, and the htonl function:
u_long = word; function htonl(hostlong : u_long) : u_long; external dll='ws2_32.dll';
The only argument passed to the htonl function is the u_long value that you want to convert to TCP/IP network byte order.
The htonl function returns the u_long value in TCP/IP network byte order.
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.