Adding the new C files too.

rmdir.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: rmdir dir...\n");
+}
+
+int
+main(int argc, char **argv)
+{
+	argv++;;
+	if(!*argv)
+		usage();
+
+	while(*argv) {
+		if(rmdir(*argv++) == -1)
+			fprintf(stderr, "rmdir: '%s': %s\n",
+					argv[-1], strerror(errno));
+	}
+
+	return 0;
+}
+