Computers differ their word-byte order, called `endianness'. A
little-endian computer has its least significant byte at the byte having the
lower address of a two-byte value, whereas a big-endian computer has its least
significant byte at at the byte having the higher address of a two-byte
value. In order to allow these computers to communicate over over Internet,
host byte order was designed. Objects of the class FBB::InetAddress
may be used to convert between network byte order and host byte order (and
vice versa).
The class only has a few public members. Most members are protected, and
FBB::InetAddress is therefore primarily used as a base class from which
other classes are derived. In practice there will be little need to construct
objects of the class FBB::InetAddress, which is primarily a support class
for the FBB socket-classes.
Internally, all data are stored in network byte order.
As the class' constructors depend on the proper functioning of members of
the FBB:GetHostent class, the class' objects can only be constructed when
the host whose name or address is searched can be resolved by a name
resolution process, e.g., bind(1).
Objects of the class FBB::InetAddress store address information about
a host in a struct sockaddr_in data member. A struct sockaddr_in is
the data type used to represent socket addresses in the Internet namespace.
It has the following members:
sa_family_t sin_family:
This identifies the address family or format of the socket
address. It holds the value AF_INET.
struct in_addr sin_addr:
This is the Internet address of the host machine stored as a binary
value.
size_t short int sin_port:
This field holds the port number.
NAMESPACE
FBB
All constructors, members, operators and manipulators, mentioned in this
man-page, are defined in the namespace FBB.
INHERITS FROM
-
PROTECTED CONSTRUCTORS
InetAddress(std::string const &host, uint16_t port):
This constructor expects a host name or dotted decimal address and
and an (size_t) port number, and determines the host's address
information. An FBB::Exception exception is thrown if the address could not be
determined.
InetAddress(uint16_t port):
This constructor constructs the `generic' address information that is
used when constructing, e.g. server sockets.
InetAddress(sockaddr_in const &address):
This constructor constructs an FBB::InetAddress object from an
initialized sockaddr_in object. It is primarily used to promote a
sockaddr_in to an FBB::InetAddresss.
The (public) copy constructor is available.
MEMBER FUNCTIONS
uint16_t port() const:
Accessor returning the object's port value.
std::string dottedDecimalAddress() const:
Accessor returning the object's Internet address as a dotted decimal
string. If the address could not be determined, an FBB::Exception object is
thrown.
size_t size() const:
Accessor returning the size of the object's sockaddr_in (address)
information.
sockaddr const *sockaddrPtr() const:
Accessor returning the pointer to the object's sockaddr data
member.
sockaddr_in const *sockaddr_inPtr() const:
Accessor returning the pointer to the object's sockaddr_in data
member.
PROTECTED MEMBER FUNCTIONS
sockaddr *sockaddrPtr():
This member returns the object's address information as a pointer to a
modifiable struct sockaddr. This allows (contrary to the public member
having the same name) derived objects to manipulate the object's address
information directly.
sockaddr_in *sockaddr_inPtr():
This member returns the object's address information as a pointer to a
modifiable struct sockaddr_in. This allows (contrary to the public member
having the same name) derived objects to manipulate the object's address
information directly.
EXAMPLE
#include <iostream>
#include <bobcat/inetaddress>
#include <bobcat/errno>
using namespace std;
using namespace FBB;
InetAddress X()
{
class A: public InetAddress
{
public:
A(uint16_t port)
:
InetAddress(port)
{}
};
return A(2000);
}
int main(int argc, char **argv)
try
{
InetAddress const &ia = X();
cout << "A InetAddress was constructed for port " << ia.port() <<
endl;
cout << "It has the generic `ANY' address: " <<
ia.dottedDecimalAddress() << endl;
return 0;
}
catch (Errno const &e)
{
cout << "Exception: " << e.why() << endl;
}