-extern size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
-extern size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
-extern size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
+size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
+size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
+size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);