dir(4) Kernel Interfaces Manual dir(4)
NAME
dir - Format of directories
SYNOPSIS
#include <sys/types.h> #include <dirent.h>
DESCRIPTION
A directory behaves like an ordinary file except that no user may write into a directory. The fact that a file is a directory is indicated
by a bit in the flag word of its inode entry. See the fs reference page.
The POSIX standard way of returning directory entries is in directory entry structures, which are of variable length. Each directory entry
has a struct direct at the front of it, containing its inode number, the length of the entry, and the length of the name contained in the
entry. These are followed by the name padded to a 4-byte boundary with null bytes. All names are guaranteed null terminated. The maximum
length of a name in a directory is _D_NAME_MAX.
By convention, the first two entries in each directory are for . (dot) and .. (dot-dot). The first is an entry for the directory itself.
The second is for the parent directory. The meaning of .. (dot-dot) is modified for the root directory (/) of the master file system,
where .. (dot-dot) has the same meaning as . (dot).
RELATED INFORMATION
Functions: opendir(3)
Files: fs(4) delim off
dir(4)
