exit if the current X11 session terminates

[wall-notify/wall-notify.git] / src / wall-notify.c

diff --git a/src/wall-notify.c b/src/wall-notify.c
index 7fb3b33cbc0bdaaf2e7436abf77bd7ca4b8d4fa1..40cdfe587870bc46f6ae5cbfc6b8c0308a74d70e 100644 (file)
--- a/src/wall-notify.c
+++ b/src/wall-notify.c
@@ -42,6 +42,10 @@
 #ifdef USE_UTMPX
 # include <utmpx.h>
 #endif
+#ifndef DONT_USE_X11
+# include <pthread.h>
+# include <X11/Xlib.h>
+#endif
 
 
 static void sig_handler(int signal) {
@@ -290,6 +294,27 @@ static void handle_wall(int fd, char **argv) {
         pass_buffer_to_program(buffer, (size_t)r, argv);
     }
 }
+#ifndef DONT_USE_X11
+static void *x11_event_loop_thread(void *unused) {
+    Display *display;
+    XEvent event;
+
+    (void)unused;
+
+    pthread_detach(pthread_self());
+
+    display = XOpenDisplay(NULL);
+    if (!display) {
+        fprintf(stderr, "failed to connect to X server\n");
+        exit(EXIT_FAILURE);
+    }
+
+    /* Do nothing. We just want to die if the X11 session is closed. */
+    while (1) {
+        XNextEvent(display, &event);
+    }
+}
+#endif
 
 static void usage(const char *argv0) {
     fprintf(stderr, "usage: %s <cmd args..>\n", argv0);
@@ -333,6 +358,19 @@ int main(int argc, char **argv) {
         exit(EXIT_FAILURE);
     }
 
+#ifndef DONT_USE_X11
+    /* Start a thread which connects to X11. This way we die if the user logs
+     * out of its X11 session. */
+    {
+        pthread_t tid;
+
+        if (pthread_create(&tid, NULL, x11_event_loop_thread, NULL) != 0) {
+            perror("pthread_create");
+            exit(EXIT_FAILURE);
+        }
+    }
+#endif
+
     /* Cleanup on signals. Necessary before login(). */
     setup_signals();