Searches the network database that is referenced by the
    TCPIP$NETWORK logical name for a network record with the
    specified address. If the network record is not found,
    this function may invoke the BIND resolver to search
    TCPIP$SYSTEM:NETWORKS.DAT.
    The $QIO equivalent is the IO$_ACPCONTROL function with the
    INETACP_FUNC$C_GETNETBYADDR subfunction code.
    Format
      #include  <netdb.h>
      struct netent *getnetbyaddr  ( long net, int type) ;

1  –  Arguments

 net
    The network number, in host byte order, of the networks database
    entry required.
 type
    The type of network being sought (AF_INET or AF_INET6).

2  –  Description

    This function finds the first network record in the networks
    database with the given address.
    The getnetbyaddr() and getnetbyname()  functions use a common
    static area for their return values. Subsequent calls to any of
    these functions overwrite any previously returned network entry.
    You must make a copy of the network entry if you want to save it.

3  –  Return Values

    x                  A pointer to an object having the netent
                       structure.
    NULL               Indicates end of file or an error.

4  –  Errors

    EINVAL             The net argument is invalid.
    ESRCH              The search failed.