From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 27 Jan 2010 06:46:23 +0000 (-0500)
Subject: Add a new "hello world" sample program
X-Git-Tag: release-2.0.4-alpha~54
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=becb9f9cd320d9b3ac571ffc788a01423568e9d0;p=libevent

Add a new "hello world" sample program
---

diff --git a/.gitignore b/.gitignore
index 9ecd8cd0..82d6c881 100644
--- a/.gitignore
+++ b/.gitignore
@@ -55,6 +55,7 @@ libevent.pc
 
 /sample/dns-example
 /sample/event-test
+/sample/hello-world
 /sample/le-proxy
 /sample/signal-test
 /sample/time-test
diff --git a/sample/Makefile.am b/sample/Makefile.am
index 8c0531f9..9a376e8c 100644
--- a/sample/Makefile.am
+++ b/sample/Makefile.am
@@ -3,12 +3,13 @@ AUTOMAKE_OPTIONS = foreign no-dependencies
 LDADD = ../libevent.la
 AM_CFLAGS = -I$(top_srcdir) -I$(top_srcdir)/compat -I$(top_srcdir)/include
 
-noinst_PROGRAMS = event-test time-test signal-test dns-example
+noinst_PROGRAMS = event-test time-test signal-test dns-example hello-world
 
 event_test_sources = event-test.c
 time_test_sources = time-test.c
 signal_test_sources = signal-test.c
 dns_example_sources = dns-example.c
+hello_world_sources = hello-world.c
 
 if OPENSSL
 noinst_PROGRAMS += le-proxy
diff --git a/sample/hello-world.c b/sample/hello-world.c
new file mode 100644
index 00000000..773c8589
--- /dev/null
+++ b/sample/hello-world.c
@@ -0,0 +1,131 @@
+/*
+  This exmple 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>
+
+#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_storage ss;
+
+	struct sockaddr_in sin;
+
+	base = event_base_new();
+	if (!base) {
+		fprintf(stderr, "Could not initialize libevent!\n");
+		return 1;
+	}
+
+	memset(&sin, 0, sizeof(sin));
+	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);
+}