plucky (3) serversocket.3bobcat.gz
NAME
FBB::ServerSocket - Server socket accepting Internet connection requests
SYNOPSIS
#include <bobcat/serversocket>
Linking option: -lbobcat
DESCRIPTION
An FBB::ServerSocket may be constructed to listen for connection requests from the Internet or from the
local host. 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 that requested 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.
A Unix Domain server socket can be defined using FBB::LocalServerSocket.
NAMESPACE
FBB
All constructors, members, operators and manipulators, mentioned in this man-page, are defined in the
namespace FBB.
INHERITS FROM
FBB::SocketBase
CONSTRUCTOR
o ServerSocket(size_t port):
This constructor initializes an FBB::ServerSocket object, which will listen for connections at the
specified port. The construction of the socket does not mean that the FBB::ServerSocket object is
actually listening for connections. To start listening, the member listen() should be used.
Copy and move constructors (and assignment operators) are not available.
MEMBER FUNCTIONS
All members of FBB::SocketBase (and thus of FBB::InetAddress) are available, as FBB::ServerSocket
inherits from FBB::SocketBase.
o void listen(size_t backlog = 5, bool blocking = true):
The listen() member defines the way the FBB::ServerSocket will listen for clients requesting a
connection. It can be used only once with a FBB::ServerSocket. An FBB::Exception object is thrown
if listening fails, if the constructor could not create a socket, or if the SocketBase base class
could not properly be constructed.
The listen() member’s backlog parameter defines the size of the FBB::ServerSocket’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 SocketBase accept():
The accept() member returns an FBB::SocketBase object containing information about the client
whose connection request was accepted. The FBB::SocketBase object’s socket value may be used to
initialize streams that can be used to communicate with the client. In more complex programs the
FBB::SocketBase could be passed to a class derived from FBB::Fork, handling the communication with
the child as a separate (child) process.
EXAMPLE
See also the clientsocket(3bobcat) example. #include <iostream> #include <string> #include <bobcat/serversocket> #include <bobcat/ifdstream> #include <bobcat/ofdstream> using namespace std; using namespace FBB; int main(int argc, char **argv) try { if (argc == 1) { cerr << "Provide server port number\n"; return 1; } size_t portnr = stoul(argv[1]); ServerSocket server(portnr); cerr << "server listens on port " << argv[1] << endl; cerr << "serversocket returns:\n" << "address = " << server.dottedDecimalAddress() << "\n" "port = " << server.port() << endl; int fd = server.socket(); // open the socket’s descriptor cout << "File descriptor of the socket is " << fd << "\n" "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) { SocketBase fdb = server.accept(); int fd = fdb.socket(); cerr << "Client FD = " << fd << ", " << endl << "address = " << fdb.dottedDecimalAddress() << ", " << endl << "communication through port " << fdb.port() << 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), clientsocket(3bobcat), fork(3bobcat), ifdstream(3bobcat), ifdbuf(3bobcat), inetaddress(3bobcat), localserversocket(3bobcat), ofdstream(3bobcat), ofdstream(3bobcat), select(2), selector(3bobcat), socketbase(3bobcat)
BUGS
None Reported.
BOBCAT PROJECT FILES
o https://fbb-git.gitlab.io/bobcat/: gitlab project page;
o bobcat_6.06.02-x.dsc: detached signature;
o bobcat_6.06.02-x.tar.gz: source archive;
o bobcat_6.06.02-x_i386.changes: change log;
o libbobcat1_6.06.02-x_*.deb: debian package containing the libraries;
o libbobcat1-dev_6.06.02-x_*.deb: debian package containing the libraries, headers and manual pages;
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).