/in/l6.c: In function 'main':
/in/l6.c:11:47: error: 'DT_REG' undeclared (first use in this function)
             printf("%d %s\n", (file->d_type & DT_REG), file->d_name);
                                               ^~~~~~
/in/l6.c:11:47: note: each undeclared identifier is reported only once for each function it appears in