Provided by: libbobcat-dev_4.08.02-2build1_amd64 
NAME
FBB::LocalServerSocket - Unix Domain Server socket accepting connection requests
SYNOPSIS
#include <bobcat/localserversocket>
Linking option: -lbobcat
DESCRIPTION
An FBB::LocalServerSocket defines a Unix Domain server socket, listening for connection
requests from the local host using a Unix Domain socket. Connection requests may be
accepted in either blocking or non-blocking modes. When a connection is accepted a socket
is returned which may be used to read information from or write information to the client
requesting the connection. The socket that is made available is a file descriptor which
may be used to initialize a std::istream and/or std::ostream. The std::istream is used to
read information from the client process; the std::ostream is used to send information to
the client process. Since a socket may be considered a file descriptor the available
FBB::IFdStream, FBB::IFdStreamBuf, FBB::OFdStream, and FBB::OFdStreamBuf classes may be
used profitably here. Note that having available a socket does not mean that this defines
the communication protocol. It is (still) the responsibility of the programmer to comply
with an existing protocol or to implement a tailor-made protocol. The latter situation
implies that the sequence of input- and output operations is defined by the programmer.
NAMESPACE
FBB
All constructors, members, operators and manipulators, mentioned in this man-page, are
defined in the namespace FBB.
INHERITS FROM
FBB::LocalSocketBase
ENUMERATION
The following enumeration is defined in th class FBB::LocalServerSocket:
enum Socket
This enumeration holds two values:
o KEEP:
When this value is specified at construction time, the file representing the Unix
Domain Socket is not removed when the LocalServerSocket is destroyed.
o UNLINK:
When this value is specified at construction time, the file representing the Unix
Domain Socket is removed when the LocalServerSocket is destroyed. As a socket
cannot be reused, this is the default value used with the LocalServerSocket
constructor.
CONSTRUCTOR
o LocalServerSocket():
This constructor creates an empty (non-functioning) FBB::LocalServerSocket object.
Before it can be used, the open() member must be called (see below).
o LocalServerSocket(string const &name, Socket action = UNLINK) throw (Exception):
This constructor initializes an FBB::LocalServerSocket object, which will listen
for connection requests using the named Unix Domain socket. An FBB::Exception is
thrown if the socket could not be constructed. If the constructor is given a second
argument FBB::LocalServerSocket::KEEP, the constructed socket is not unlinked when
the FBB::LocalServerSocket object is destroyed. The construction of the socket
does not mean that the FBB::LocalServerSocket object is actually listening for
connections. To start listening, the member listen() should be called. The copy
constructor is not available.
MEMBER FUNCTIONS
o size_t accept():
The accept() member returns an size_t which is a file descriptor (socket) that may
be used to communicate with the client requesting the connection. In more complex
programs the returned file descriptor (socket) could be passed to a class derived
from FBB::Fork, handling the communication with the child as a separate (child)
process.
o void listen(size_t backlog = 5, bool blocking = true):
The listen() member defines the way the FBB::LocalServerSocket will listen for
clients requesting a connection. It can be used only once with a
FBB::LocalServerSocket. An FBB::Exception object is thrown if listening fails.
The listen() member’s backlog parameter defines the size of the
FBB::LocalServerSocket’s internal queue in which connection requests may be stored
waiting for their turn to be serviced. When backlog requests are waiting and
another request arrives, then that request is lost.
The member’s second parameter, blocking, is used to control the blocking mode. By
default, blocking is used, and listen() will wait until a connection is
established. This is ok in situations where clients connect infrquently and for
relatively short time intervals. Otherwise, in more complex programs, an
FBB::Selector object can be used to sense input on the server socket and/or on
various client sockets.
o void open(string const &name, Socket action = UNLINK):
This member prepares a FBB::LocalServerSocket object for use. It should only be
used in combination with the default constructor. Following open() the
FBB:::LocalServerSocket object will be able to listen for connection requests using
the named Unix Domain socket. An FBB::Exception is thrown if the socket could not
be constructed. If the a second argument FBB::LocalServerSocket::KEEP, is provided
the constructed socket is not unlinked when the FBB::LocalServerSocket object is
destroyed. The construction of the socket does not mean that the
FBB::LocalServerSocket object is actually listening for connections. To start
listening, the member listen() should be called next.
EXAMPLE
See also the localclientsocket(3bobcat) example.
#include <iostream>
#include <bobcat/localserversocket>
#include <bobcat/ifdstream>
#include <bobcat/ofdstream>
using namespace std;
using namespace FBB;
int main(int argc, char **argv)
try
{
if (argc == 1)
{
cerr << "Provide local filename, e.g., /tmp/uds\n";
return 1;
}
LocalServerSocket server(argv[1]);
cerr << "server using `" << argv[1] << "’" << endl;
cout <<
"The server terminates when it receives a single `q’ on a line\n"
"A connection is terminated when no input is received anymore.\n"
"Then another connection is possible" << endl;
server.listen(); // listen in blocking mode
while (true)
{
int fd = server.accept();
cerr << "Client FD = " << fd << ", " << endl;
IFdStream in(fd); // stream to read from client
OFdStream out(fd); // stream to write to client
string cmd;
while (getline(in, cmd))
{
cout << "Got: " << cmd << endl;
out << "Got: " << cmd << "\r" << endl;
if (cmd[0] == ’q’)
return 0;
}
cout << "Ready for another connection\n";
}
}
catch (Exception const &err)
{
cerr <<
err.what() << endl <<
"Server socket on port " << argv[1] <<
" can’t be opened" << endl;
return -1;
}
FILES
bobcat/serversocket - defines the class interface
SEE ALSO
bobcat(7), localclientsocket(3bobcat), fork(3bobcat), ifdstream(3bobcat),
ifdstreambuf(3bobcat), localsocketbase(3bobcat), ofdstream(3bobcat), ofdstream(3bobcat),
select(2), selector(3bobcat), serversocket(3bobcat)
BUGS
None Reported.
DISTRIBUTION FILES
o bobcat_4.08.02-x.dsc: detached signature;
o bobcat_4.08.02-x.tar.gz: source archive;
o bobcat_4.08.02-x_i386.changes: change log;
o libbobcat1_4.08.02-x_*.deb: debian package holding the libraries;
o libbobcat1-dev_4.08.02-x_*.deb: debian package holding the libraries, headers and
manual pages;
o http://sourceforge.net/projects/bobcat: public archive location;
BOBCAT
Bobcat is an acronym of `Brokken’s Own Base Classes And Templates’.
COPYRIGHT
This is free software, distributed under the terms of the GNU General Public License
(GPL).
AUTHOR
Frank B. Brokken (f.b.brokken@rug.nl).