extern void set_cleanup_func(void (* f)());
/* If "err" == 0, do nothing. Else, clean up and exit with an error message that
- * consists, first, of "msg" or (if "msg" is a NULL pointer) a generic "Details
- * unknown", secondly of "err" as the "internal error code", and thirdly of
- * errno if it is non-zero.
+ * consists of "msg" or (if "msg" is NULL pointer) a generic "Details unknown"
+ * and of errno's content (if it is non-zero).
*/
-extern void exit_err(int err, char * msg);
+extern void exit_err(int err, const char * msg);
/* Do exit_err() with "msg" as: "Trouble in ".parent." with ".child."." */
-extern void exit_trouble(int err, char * parent, char * child);
+extern void exit_trouble(int err, const char * parent, const char * child);