The structure, struct dirent
refers to directory entry.
http://www.gnu.org/software/libc/manual/html_node/Directory-Entries.html
In linux it is defined as:
struct dirent {
ino_t d_ino; /* inode number */
off_t d_off; /* offset to the next dirent */
unsigned short d_reclen; /* length of this record */
unsigned char d_type; /* type of file; not supported
by all file system types */
char d_name[256]; /* filename */
};
refer: man readdir
Or just look for “dirent.h” in the include directory.