fprintf(sf,"%d\n", (seq_nbr+1) & UCHAR_MAX);
fflush(sf); /* fflush because a process may read it between the do_unlock and fclose */
fprintf(sf,"%d\n", (seq_nbr+1) & UCHAR_MAX);
fflush(sf); /* fflush because a process may read it between the do_unlock and fclose */