+void replace_prefix (char **pname, const char *samp, size_t slen,
+ const char *repl, size_t rlen);
+
+typedef struct namebuf *namebuf_t;
+namebuf_t namebuf_create (const char *dir);
+void namebuf_free (namebuf_t buf);
+char *namebuf_name (namebuf_t buf, const char *name);