-void *open_settings_r(char *sessionname);
-char *read_setting_s(void *handle, char *key, char *buffer, int buflen);
-int read_setting_i(void *handle, char *key, int defvalue);
+void *open_settings_r(const char *sessionname);
+char *read_setting_s(void *handle, const char *key, char *buffer, int buflen);
+int read_setting_i(void *handle, const char *key, int defvalue);
+int read_setting_filename(void *handle, const char *key, Filename *value);
+int read_setting_fontspec(void *handle, const char *key, FontSpec *font);