diff -r ba40af6cf815 -r 2383ed4da507 c++/domain-socket-bridge/domain-socket-bridge.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/c++/domain-socket-bridge/domain-socket-bridge.cpp	Sun Nov 20 20:40:30 2016 +0100
@@ -0,0 +1,224 @@
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string>
+#include <regex>
+
+#include <event2/bufferevent.h>
+#include <event2/buffer.h>
+#include <event2/listener.h>
+#include <event2/util.h>
+#include <event2/event.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+using namespace std;
+
+static const char MESSAGE[] = "Hello, World!\n";
+
+static const char PATH[] = "./roura";
+
+static const string COMMAND_EXIT("exit\n");
+
+static void listener_cb(evutil_socket_t, short, void *);
+static void conn_read_cb(struct bufferevent *, void *);
+static void conn_write_cb(struct bufferevent *, void *);
+static void conn_event_cb(struct bufferevent *, short, void *);
+static void signal_cb(evutil_socket_t, short, void *);
+static void print_socket_info(int, int);
+
+int main(int argc, char **argv) {
+	printf("%4s %8s\n", "*", "STARTED");
+	struct event_base *base;
+	evutil_socket_t listener;
+	struct event *listener_event;
+	struct event *signal_event;
+
+	struct sockaddr_un sun;
+
+	setvbuf(stdout, NULL, _IONBF, 0);
+
+	base = event_base_new();
+	if (!base) {
+		printf("%4s %8s %s\n", "*", "ERROR", "unable to initialize libevent");
+		return 1;
+	}
+
+	memset(&sun, 0, sizeof (sun));
+	sun.sun_family = AF_UNIX;
+	strcpy(sun.sun_path, PATH);
+
+	listener = socket(AF_UNIX, SOCK_STREAM, 0);
+	evutil_make_socket_nonblocking(listener);
+
+	if (bind(listener, (struct sockaddr*) &sun, sizeof (sun)) < 0) {
+		printf("%4s %8s %s: %s\n", "*", "ERROR", "unable to create domain socket:", PATH);
+		return 1;
+	}
+
+	if (listen(listener, 16) < 0) {
+		printf("%4s %8s %s\n", "*", "ERROR", "unable to listen");
+		return 1;
+	}
+
+	// identifikátor serverového soketu (v současnosti číslo FD)
+	printf("%4s %8s listening at: sun_path = %s → socketId = %d\n", "*", "SOCKET", sun.sun_path, listener);
+
+	listener_event = event_new(base, listener, EV_READ | EV_PERSIST, listener_cb, (void*) base);
+
+	if (!listener_event) {
+		printf("%4s %8s %s\n", "*", "ERROR", "unable to do event_new()");
+		return 1;
+	}
+
+	event_add(listener_event, NULL);
+
+	signal_event = evsignal_new(base, SIGINT, signal_cb, (void *) base);
+
+	if (!signal_event || event_add(signal_event, NULL) < 0) {
+		printf("%4s %8s %s\n", "*", "ERROR", "unable to create/add a signal event");
+		return 1;
+	}
+
+	event_base_dispatch(base);
+
+	event_free(listener_event);
+	event_free(signal_event);
+	event_base_free(base);
+
+	// smažeme soket na disku / soubor -- jinak by program příště spadl na bind()
+	// TODO: co když soket někdo přesune a místo něj dá jiný soubor?
+	unlink(PATH);
+
+	printf("%4s %8s\n", "*", "FINISHED");
+	return 0;
+}
+
+static void listener_cb(evutil_socket_t listener, short event, void *user_data) {
+	struct event_base *base = (event_base *) user_data;
+	struct bufferevent *bev;
+
+	struct sockaddr_storage ss;
+	socklen_t slen = sizeof (ss);
+	int fd = accept(listener, (struct sockaddr*) &ss, &slen);
+
+	// identifikátor navázaného spojení (v současnosti číslo FD)
+	int * connectionId = (int*) malloc(sizeof (fd));
+	*connectionId = fd;
+
+	if (fd < 0) {
+		printf("%4d %8s %s\n", *connectionId, "ERROR", "unable to accept()");
+		return;
+	} else if (fd > FD_SETSIZE) {
+		// FD_SETSIZE = 1024 -- Proč? Co když bude spojení víc?
+		printf("%4d %8s fd (%d) > FD_SETSIZE (%d)\n", *connectionId, "ERROR", fd, FD_SETSIZE);
+		close(fd);
+		return;
+	}
+
+	evutil_make_socket_nonblocking(fd);
+
+
+	bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
+	if (!bev) {
+		printf("%4d %8s %s\n", *connectionId, "ERROR", "constructing bufferevent");
+		event_base_loopbreak(base);
+		return;
+	}
+
+
+
+
+	bufferevent_setcb(bev, conn_read_cb, conn_write_cb, conn_event_cb, (void*) connectionId);
+	bufferevent_enable(bev, EV_READ | EV_WRITE);
+
+	printf("%4d %8s somebody has connected: socketId = %d → connectionId = %d\n", *connectionId, "CONN", listener, *connectionId);
+	print_socket_info(*connectionId, fd);
+
+	bufferevent_write(bev, MESSAGE, strlen(MESSAGE));
+}
+
+static void conn_read_cb(struct bufferevent *bev, void *user_data) {
+	int connectionId = *((int*) user_data);
+
+	/* This callback is invoked when there is data to read on bev. */
+	struct evbuffer *input = bufferevent_get_input(bev);
+	struct evbuffer *output = bufferevent_get_output(bev);
+	struct event_base *base = bufferevent_get_base(bev);
+
+	size_t len = evbuffer_get_length(input);
+	char *data = (char*) malloc(len);
+	evbuffer_copyout(input, data, len);
+
+
+	string dataFormated(data);
+	dataFormated = regex_replace(dataFormated, regex("\\n"), "\\n");
+	printf("%4d %8s '%s'\n", connectionId, "IN", dataFormated.c_str());
+
+	if (COMMAND_EXIT.compare(data) == 0) {
+		struct timeval delay = {2, 123};
+		printf("%4d %8s client asks us to terminate; finishing in %ld sesonds and %ld microseconds\n", connectionId, "EXIT", delay.tv_sec, delay.tv_usec);
+		event_base_loopexit(base, &delay);
+	}
+
+	evbuffer_add(output, "echo: ", 6);
+	/* Copy all the data from the input buffer to the output buffer. */
+	evbuffer_add_buffer(output, input);
+	free(data);
+}
+
+static void conn_write_cb(struct bufferevent *bev, void *user_data) {
+	int connectionId = *((int*) user_data);
+
+	struct evbuffer *output = bufferevent_get_output(bev);
+	if (evbuffer_get_length(output) == 0) {
+		printf("%4d %8s\n", connectionId, "FLUSH");
+		/* nebudeme ukončovat spojení
+		bufferevent_free(bev);
+		 */
+	} else {
+		// FIXME: sem to nikdy nepřijde
+		size_t len = evbuffer_get_length(output);
+		char *data = (char*) malloc(len);
+		evbuffer_copyout(output, data, len);
+		printf("%4d %8s '%s'\n", connectionId, "OUT", data);
+		free(data);
+	}
+}
+
+static void conn_event_cb(struct bufferevent *bev, short events, void *user_data) {
+	int connectionId = *((int*) user_data);
+
+	if (events & BEV_EVENT_EOF) {
+		printf("%4d %8s\n", connectionId, "CLOSE");
+	} else if (events & BEV_EVENT_ERROR) {
+		printf("%4d %8s %s\n", connectionId, "ERROR", strerror(errno));
+	} else {
+		printf("%4d %8s\n", connectionId, "OTHER");
+		// None of the other events can happen here, since we haven't enabled timeouts
+	}
+
+	bufferevent_free(bev);
+	free(user_data);
+}
+
+static void signal_cb(evutil_socket_t sig, short events, void *user_data) {
+	struct event_base *base = (event_base *) user_data;
+	struct timeval delay = {2, 123};
+
+	printf("\n%4s %8s got SIGINT (Ctrl+C); finishing in %ld sesonds and %ld microseconds\n", "*", "SIGNAL", delay.tv_sec, delay.tv_usec);
+
+	event_base_loopexit(base, &delay);
+}
+
+static void print_socket_info(int connectionId, int fd) {
+	struct ucred cr;
+	unsigned int cl = sizeof (cr);
+
+	if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &cl) == 0) {
+		printf("%4d %8s client identification: pid=%d, uid=%d, gid=%d\n", connectionId, "CONN", cr.pid, cr.uid, cr.gid);
+	}
+}
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