#include <sys/dir.h>
BSD / POSIX › Files & directories

sys/dir.h

includes: dirent.h
2 macros

macrodirect

Backwards compatibility.
#define direct dirent

macroDIRSIZ

The DIRSIZ macro gives the minimum record length which will hold the directory entry. This requires the amount of space in struct direct without the d_name field, plus enough space for the name with a terminating null byte (dp->d_namlen+1), rounded up to a 4 byte boundary.
#define DIRSIZ(dp) (((unsigned long)&((struct direct *)0)->d_name + (dp)->d_namlen+1 + 3) & ~3)