OpenSolaris 2009.06 - man page for dir (opensolaris section 4)

dir_ufs(4)				   File Formats 			       dir_ufs(4)

NAME
       dir_ufs, dir - format of ufs directories

SYNOPSIS
       #include <sys/param.h>

       #include <sys/types.h>

       #include <sys/fs/ufs_fsdir.h>

DESCRIPTION
       A directory consists of some number of blocks of DIRBLKSIZ bytes, where	DIRBLKSIZ is cho-
       sen such that it can be transferred to disk in a single atomic operation, for example, 512
       bytes on most machines.

       Each   DIRBLKSIZ-byte  block contains some number of directory entry structures, which are
       of variable length.  Each directory entry has a	struct direct at the front  of	it,  con-
       taining its inode number, the length of the entry, and the length of the name contained in
       the entry.  These entries 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 direc-
       tory is	MAXNAMLEN.

	 #define DIRBLKSIZ			 DEV_BSIZE
	 #define MAXNAMLEN			 256
	 struct direct {
		 ulong_t  d_ino;		 /* inode number of entry */
		 ushort_t d_reclen;		 /* length of this record */
		 ushort_t d_namlen;		 /* length of string in d_name */
		 char	  d_name[MAXNAMLEN + 1]; /* maximum name length */
	 };

ATTRIBUTES
       See attributes(5) for a description of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Unstable			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       attributes(5), ufs(7FS)

SunOS 5.11				   16 Apr 2003				       dir_ufs(4)