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-rw-r--r--libevent/sample/hello-world.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/libevent/sample/hello-world.c b/libevent/sample/hello-world.c
new file mode 100644
index 0000000..a13e06a
--- /dev/null
+++ b/libevent/sample/hello-world.c
@@ -0,0 +1,140 @@
+/*
+ This example program provides a trivial server program that listens for TCP
+ connections on port 9995. When they arrive, it writes a short message to
+ each client connection, and closes each connection once it is flushed.
+
+ Where possible, it exits cleanly in response to a SIGINT (ctrl-c).
+*/
+
+
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+#include <signal.h>
+#ifndef _WIN32
+#include <netinet/in.h>
+# ifdef _XOPEN_SOURCE_EXTENDED
+# include <arpa/inet.h>
+# endif
+#include <sys/socket.h>
+#endif
+
+#include <event2/bufferevent.h>
+#include <event2/buffer.h>
+#include <event2/listener.h>
+#include <event2/util.h>
+#include <event2/event.h>
+
+static const char MESSAGE[] = "Hello, World!\n";
+
+static const int PORT = 9995;
+
+static void listener_cb(struct evconnlistener *, evutil_socket_t,
+ struct sockaddr *, int socklen, void *);
+static void conn_writecb(struct bufferevent *, void *);
+static void conn_eventcb(struct bufferevent *, short, void *);
+static void signal_cb(evutil_socket_t, short, void *);
+
+int
+main(int argc, char **argv)
+{
+ struct event_base *base;
+ struct evconnlistener *listener;
+ struct event *signal_event;
+
+ struct sockaddr_in sin = {0};
+#ifdef _WIN32
+ WSADATA wsa_data;
+ WSAStartup(0x0201, &wsa_data);
+#endif
+
+ base = event_base_new();
+ if (!base) {
+ fprintf(stderr, "Could not initialize libevent!\n");
+ return 1;
+ }
+
+ sin.sin_family = AF_INET;
+ sin.sin_port = htons(PORT);
+
+ listener = evconnlistener_new_bind(base, listener_cb, (void *)base,
+ LEV_OPT_REUSEABLE|LEV_OPT_CLOSE_ON_FREE, -1,
+ (struct sockaddr*)&sin,
+ sizeof(sin));
+
+ if (!listener) {
+ fprintf(stderr, "Could not create a listener!\n");
+ return 1;
+ }
+
+ signal_event = evsignal_new(base, SIGINT, signal_cb, (void *)base);
+
+ if (!signal_event || event_add(signal_event, NULL)<0) {
+ fprintf(stderr, "Could not create/add a signal event!\n");
+ return 1;
+ }
+
+ event_base_dispatch(base);
+
+ evconnlistener_free(listener);
+ event_free(signal_event);
+ event_base_free(base);
+
+ printf("done\n");
+ return 0;
+}
+
+static void
+listener_cb(struct evconnlistener *listener, evutil_socket_t fd,
+ struct sockaddr *sa, int socklen, void *user_data)
+{
+ struct event_base *base = user_data;
+ struct bufferevent *bev;
+
+ bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
+ if (!bev) {
+ fprintf(stderr, "Error constructing bufferevent!");
+ event_base_loopbreak(base);
+ return;
+ }
+ bufferevent_setcb(bev, NULL, conn_writecb, conn_eventcb, NULL);
+ bufferevent_enable(bev, EV_WRITE);
+ bufferevent_disable(bev, EV_READ);
+
+ bufferevent_write(bev, MESSAGE, strlen(MESSAGE));
+}
+
+static void
+conn_writecb(struct bufferevent *bev, void *user_data)
+{
+ struct evbuffer *output = bufferevent_get_output(bev);
+ if (evbuffer_get_length(output) == 0) {
+ printf("flushed answer\n");
+ bufferevent_free(bev);
+ }
+}
+
+static void
+conn_eventcb(struct bufferevent *bev, short events, void *user_data)
+{
+ if (events & BEV_EVENT_EOF) {
+ printf("Connection closed.\n");
+ } else if (events & BEV_EVENT_ERROR) {
+ printf("Got an error on the connection: %s\n",
+ strerror(errno));/*XXX win32*/
+ }
+ /* None of the other events can happen here, since we haven't enabled
+ * timeouts */
+ bufferevent_free(bev);
+}
+
+static void
+signal_cb(evutil_socket_t sig, short events, void *user_data)
+{
+ struct event_base *base = user_data;
+ struct timeval delay = { 2, 0 };
+
+ printf("Caught an interrupt signal; exiting cleanly in two seconds.\n");
+
+ event_base_loopexit(base, &delay);
+}