+static size_t readname (char **, size_t *, FILE *);
+
+#if ! defined ADDITIONAL_DEFAULT_SHELLS && defined __MSDOS__
+# define ADDITIONAL_DEFAULT_SHELLS \
+ "c:/dos/command.com", "c:/windows/command.com", "c:/command.com",
+#else
+# define ADDITIONAL_DEFAULT_SHELLS /* empty */
+#endif