Add PBD::tmp_writable_directory utility function to pbd/file_utils.h/cc

libs/pbd/file_utils.cc

@@ -468,4 +468,21 @@ remove_directory (const std::string& dir)
 	remove_directory_internal (dir, 0, 0, false);
 }
 
+string
+tmp_writable_directory (const char* domain, const string& prefix)
+{
+	std::string tmp_dir = Glib::build_filename (g_get_tmp_dir(), domain);
+	std::string dir_name;
+	std::string new_test_dir;
+	do {
+		ostringstream oss;
+		oss << prefix;
+		oss << g_random_int ();
+		dir_name = oss.str();
+		new_test_dir = Glib::build_filename (tmp_dir, dir_name);
+		if (Glib::file_test (new_test_dir, Glib::FILE_TEST_EXISTS)) continue;
+	} while (g_mkdir_with_parents (new_test_dir.c_str(), 0755) != 0);
+	return new_test_dir;
+}
+
 } // namespace PBD

libs/pbd/pbd/file_utils.h

@@ -232,6 +232,22 @@ LIBPBD_API int clear_directory (const std::string& dir, size_t* size = 0,
  */
 LIBPBD_API void remove_directory (const std::string& dir);
 
+/**
+ * Create a temporary writable directory in which to create
+ * temporary files. The directory will be created under the
+ * top level "domain" directory.
+ *
+ * For instance tmp_writable_directory ("pbd", "foo") on POSIX
+ * systems may return a path to a new directory something like
+ * to /tmp/pbd/foo-1423
+ *
+ * @param domain The top level directory
+ * @param prefix A prefix to use when creating subdirectory name
+ *
+ * @return new temporary directory
+ */
+LIBPBD_API std::string tmp_writable_directory (const char* domain, const std::string& prefix);
+
 } // namespace PBD
 
 #endif