1 files changed, 56 insertions, 0 deletions
diff --git a/.config/wmii-hg/rbar_clock.c b/.config/wmii-hg/rbar_clock.c
new file mode 100644
index 0000000..ab636c2
--- /dev/null
+++ b/.config/wmii-hg/rbar_clock.c
@@ -0,0 +1,56 @@
+#include "rbar.h"
+
+#include <stdint.h> /* uint64_t */
+#include <stdlib.h> /* atexit(3p) */
+#include <sys/timerfd.h>
+#include <time.h> /* glock_gettime, localtime, strftime */
+
+const char *cleanup_id;
+
+void cleanup(void) {
+	rbar_remove(rbar_globescape(cleanup_id));
+}
+
+int update(const char *id) {
+	cleanup_id = id;
+	atexit(cleanup);
+
+	int timer = timerfd_create(CLOCK_REALTIME, 0);
+	if (timer < 0)
+		error(1, errno, "timerfd_create");
+
+	struct timespec now;
+	if (clock_gettime(CLOCK_REALTIME, &now) < 0)
+		error(1, errno, "clock_gettime");
+
+	struct itimerspec spec = {
+		.it_interval = (struct timespec){.tv_sec = 1, .tv_nsec = 0},
+		.it_value = (struct timespec){.tv_sec = now.tv_sec+1, .tv_nsec = 0},
+	};
+
+	if (timerfd_settime(timer, TFD_TIMER_ABSTIME, &spec, NULL) < 0)
+		error(1, errno, "timerfd_settime");
+
+	for (;;) {
+		uint64_t count;
+		if (read(timer, &count, sizeof count) != sizeof count)
+			error(1, errno, "read");
+		if (clock_gettime(CLOCK_REALTIME, &now) < 0)
+			error(1, errno, "clock_gettime");
+		char str[80];
+		if (strftime(str, sizeof str,
+			     "label %a %F %T %Z(%z)", /* apparently %:::z" is supported by date(1gnu) but not strftime(3gnu) */
+			     localtime(&now.tv_sec)) <= 0)
+			error(1, 0, "strftime wanted a really long string");
+		int err = rbar_write(id, str);
+		if (err != 0) {
+			if (err == GLOB_NOMATCH)
+				return 0;
+			return 1;
+		}
+	}
+}
+
+struct impl impl = {
+	.update = update,
+};