Move scripts to bin/ directory

bin/nbd-find-free

@@ -0,0 +1,17 @@
+#!/bin/bash
+# returns an unused nbd device
+for sys_path in /sys/block/nbd[0-9]*; do
+	[ -d "$sys_path" ] || continue
+
+	if [ -f "$sys_path/size" ] && [ "$(< "$sys_path/size")" -eq 0 ] ; then
+		TARGET="/dev/${sys_path##*/}"
+		break
+	fi
+done
+
+if [ -z "$TARGET" ]; then
+	echo "Error: no free NBD device found" >&2
+	exit 1
+fi
+
+echo $TARGET