This is the pause executable. It implements oneshot functionality in runit.

Man Page:https://man.voidlinux.org/pause
You can find pause.c here:https://github.com/void-linux/void-runit/blob/master/pause.c

pause.c

@@ -0,0 +1,19 @@
+#include <unistd.h>
+#include <signal.h>
+
+static void
+nop(int sig)
+{
+}
+
+int
+main()
+{
+  signal(SIGTERM, nop);
+  signal(SIGINT, nop);
+  signal(SIGHUP, SIG_IGN);
+
+  pause();
+
+  return 0;
+}