C Programming Error: 'struct dirent' has no member named 'd_type'

The error messages suggest that the code is trying to access the 'd_type' member of a 'struct dirent', which does not exist. The code also references the 'DT_DIR' and 'DT_REG' constants, which are not defined.

This could be due to differences in the implementation of the dirent.h header file on different systems. Some systems may support the 'd_type' member and the constants, while others may not.

To fix the error, you could try using a different approach to check whether a directory entry is a directory or a regular file. One option is to use the 'stat' function to get information about the file, and then check the 'st_mode' field to see if it represents a directory or a regular file. Another option is to use the 'opendir' and 'readdir' functions to iterate over the directory entries, and then use the 'S_ISDIR' and 'S_ISREG' macros to check if the entry is a directory or a regular file.