+ int i, compress_level = -1;
+ for (i = 0; mode[i]; ++i) if (mode[i] >= '0' && mode[i] <= '9') break;
+ if (mode[i]) compress_level = mode[i] - '0';
+ if (strchr(mode, 'u')) compress_level = 0;
+ bmode[0] = 'w'; bmode[1] = compress_level < 0? 0 : compress_level + '0'; bmode[2] = 0;