1 files changed, 38 insertions, 0 deletions
diff --git a/doc/examples/daemon-dependencies/require.c b/doc/examples/daemon-dependencies/require.c
new file mode 100644
index 0000000..e378431
--- /dev/null
+++ b/doc/examples/daemon-dependencies/require.c
@@ -0,0 +1,38 @@
+#include <bus.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#define t(stmt)  if (stmt) goto fail
+
+
+static char arg[4098];
+
+
+int
+main(int argc, char *argv[])
+{
+	bus_t bus;
+	int i;
+	if (argc < 2)
+		return fprintf(stderr, "USAGE: %s daemon...", *argv), 2;
+	t(bus_open(&bus, getenv("BUS_INIT"), BUS_WRONLY));
+
+	for (i = 1; i < argc; i++) {
+		sprintf(arg, "grep '^%s$' < \"${XDG_RUNTIME_DIR}/started-daemons\" >/dev/null", argv[i]);
+		if (WEXITSTATUS(system(arg))) {
+			sprintf(arg, "%ji require %s", (intmax_t)getppid(), argv[i]);
+			t(bus_write(&bus, arg, 0));
+		}
+	}
+
+	bus_close(&bus);
+	return 0;
+
+fail:
+	perror("require");
+	bus_close(&bus);
+	return 1;
+}
+