if (ssh_args != NULL)
sbuf_printf(cmd, "%s ", ssh_args);
if (u->port > 0)
sbuf_printf(cmd, "-P %d ", u->port);
sbuf_printf(cmd, "-p %d ", u->port);
if (u->user[0] != '\0')
sbuf_printf(cmd, "%s@", u->user);
sbuf_cat(cmd, u->host);