-char **strv_env_merge(char **x, ...) _sentinel_;
-char **strv_env_delete(char **x, ...) _sentinel_;
+char **strv_env_merge(unsigned n_lists, ...);
+char **strv_env_delete(char **x, unsigned n_lists, ...);
+
+char **strv_env_set(char **x, const char *p);
+char **strv_env_unset(char **l, const char *p);
+
+char *strv_env_get_with_length(char **l, const char *name, size_t k);
+char *strv_env_get(char **x, const char *n);
+
+char **strv_env_clean(char **l);
+
+char **strv_parse_nulstr(const char *s, size_t l);