NAME
dir — format of directories on short-name HFS file systems
SYNOPSIS
#include <sys/types.h>
#include <sys/dir.h>
Remarks
This entry describes the System V-compatible
directory format for the
HFS
file system.
It is provided strictly for backward compatibility
and compatibility with applications
expecting a System V file system environment.
It is not compatible with the similar but more general
HFS
directory format in
<dirent.h>,
which describes a format identical to that used in an
HFS
file system supporting long file names up to 255 bytes in length.
The
dirent
structure defined in
<dirent.h>
should be used in conjunction with the
directory(3C)
routines for portability to other industry
UNIX
implementations.
DESCRIPTION
A directory behaves exactly like an ordinary file, except that no
user can write into a directory.
The structure of a directory entry as given in the
<sys/dir.h>
header file is:
#define DIRSIZ 14
#define DIRSIZ_CONSTANT 14
#define DIR_PADSIZE 10
#define MAXNAMLEN 255
struct direct {
u_long d_ino; /* inode number of entry */
u_short d_reclen; /* length of this record */
u_short d_namlen; /* length of string in d_name */
char d_name[DIRSIZ_CONSTANT];
char d_pad[DIR_PADSIZE];
};
/*
* DIRSTRCTSIZ is the number of bytes in the structure
* representing a System V-compatible (14-character
* maximum file name length) HFS directory entry.
*/
#define DIRSTRCTSIZ 32 /* sizeof(struct direct) */
By convention, the first two entries in each directory are for
.
and
..
(``dot'' and ``dot dot'').
The first is an entry for the directory itself.
The second is for the parent directory.
The meaning of
..
is modified for the root directory of the master file system;
there is no parent, so
..
and
.
have the same meaning.
AUTHOR
dir
was developed by AT&T and HP.
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