io: directory: implement temporary directories and delete-on-close

io/sys/darwin/misc.c

@@ -0,0 +1,21 @@
+#include "misc.h"
+
+#include <blue/core/random.h>
+
+void z__b_io_generate_tmp_filename(char *out, size_t len)
+{
+	static const char *alphabet
+		= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+		  "01234567"
+		  "89+=-_.";
+	static const size_t alphabet_len = 67;
+
+	b_random_ctx *ctx = b_random_global_ctx();
+
+	for (size_t i = 0; i < len; i++) {
+		int v = b_random_next_int64(ctx) % alphabet_len;
+		out[i] = alphabet[v];
+	}
+
+	out[len - 1] = 0;
+}