fetch_write
if (fetch_write(conn, buf, 3) != 3) {
if (fetch_write(conn, buf, ptr - buf) != ptr - buf) {
ssize_t fetch_write(conn_t *, const char *, size_t);
w = fetch_write(io->dconn, buf, len);
fetch_write(conn, body, body_len);
return (fetch_write(io->conn, buf, len));