dirent man page on OpenDarwin

Man page or keyword search:  
man Server   3202 pages
apropos Keyword Search (all sections)
Output format
OpenDarwin logo
[printable version]

DIR(5)			    BSD File Formats Manual			DIR(5)

NAME
     dir, dirent — directory file format

SYNOPSIS
     #include <sys/types.h>
     #include <sys/dir.h>

DESCRIPTION
     Directories provide a convenient hierarchical method of grouping files
     while obscuring the underlying details of the storage medium.  A direc‐
     tory file is differentiated from a plain file by a flag in its inode(5)
     entry.  It consists of records (directory entries) each of which contains
     information about a file and a pointer to the file itself.	 Directory
     entries may contain other directories as well as plain files; such nested
     directories are refered to as subdirectories.  A hierarchy of directories
     and files is formed in this manner and is called a file system (or
     referred to as a file system tree).

     Each directory file contains two special directory entries; one is a
     pointer to the directory itself called dot ‘.’ and the other a pointer to
     its parent directory called dot-dot ‘..’.	Dot and dot-dot are valid
     pathnames, however, the system root directory ‘/’, has no parent and dot-
     dot points to itself like dot.

     File system nodes are ordinary directory files on which has been grafted
     a file system object, such as a physical disk or a partitioned area of
     such a disk.  (See mount(1) and mount(8).)

     The directory entry format is defined in the file ⟨sys/dirent.h⟩ and fur‐
     ther in the file ⟨dirent.h⟩:

     /*** Excerpt from <sys/dirent.h> ***/
     /*
      * The dirent structure defines the format of directory entries returned by
      * the getdirentries(2) system call.
      *
      * A directory entry has a struct dirent 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 MAXNAMLEN.
      * The dirent structure defines the format of directory entries returned by
      * the getdirentries(2) system call.
      */

     #ifndef _SYS_DIRENT_H
     #define _SYS_DIRENT_H

     struct dirent {
	     u_int32_t d_fileno;	     /* file number of entry */
	     u_int16_t d_reclen;	     /* length of this record */
	     u_int8_t  d_type;		     /* file type, see below */
	     u_int8_t  d_namlen;	     /* length of string in d_name */
     #ifdef _POSIX_SOURCE
	     char    d_name[255 + 1];	     /* name must be no longer than this */
     #else
     #define MAXNAMLEN	     255
	     char    d_name[MAXNAMLEN + 1];  /* name must be no longer than this */
     #endif
     };

     /*
      * File types
      */
     #define DT_UNKNOWN	      0
     #define DT_FIFO	      1
     #define DT_CHR	      2
     #define DT_DIR	      4
     #define DT_BLK	      6
     #define DT_REG	      8
     #define DT_LNK	     10
     #define DT_SOCK	     12
     #define DT_WHT	     14

     #endif /* !_SYS_DIRENT_H_ */

     -----------------------------------------

     /*** Excerpt from <dirent.h> ***/

     #ifndef _DIRENT_H
     #define _DIRENT_H

     #ifdef _POSIX_SOURCE
     typedef void *  DIR;
     #else

     #define d_ino	     d_fileno	     /* backward compatibility */

     /* definitions for library routines operating on directories. */
     #define DIRBLKSIZ	     1024

     struct _telldir;		     /* see telldir.h */

     /* structure describing an open directory. */
     typedef struct _dirdesc {
	     int     dd_fd;	     /* file descriptor associated with directory */
	     long    dd_loc;	     /* offset in current buffer */
	     long    dd_size;	     /* amount of data returned by getdirentries */
	     char    *dd_buf;	     /* data buffer */
	     int     dd_len;	     /* size of data buffer */
	     long    dd_seek;	     /* magic cookie returned by getdirentries */
	     long    dd_rewind;	     /* magic cookie for rewinding */
	     int     dd_flags;	     /* flags for readdir */
	     pthread_mutex_t dd_lock; /* for thread locking */
	     struct _telldir *dd_td; /* telldir position recording */
     } DIR;

     #define dirfd(dirp)     ((dirp)->dd_fd)

     /* flags for opendir2 */
     #define DTF_HIDEW	     0x0001  /* hide whiteout entries */
     #define DTF_NODUP	     0x0002  /* don't return duplicate names */
     /* structure describing an open directory. */
     typedef struct _dirdesc {
	     int     dd_fd;	     /* file descriptor associated with directory */
	     long    dd_loc;	     /* offset in current buffer */
	     long    dd_size;	     /* amount of data returned by getdirentries */
	     char    *dd_buf;	     /* data buffer */
	     int     dd_len;	     /* size of data buffer */
	     long    dd_seek;	     /* magic cookie returned by getdirentries */
	     long    dd_rewind;	     /* magic cookie for rewinding */
	     int     dd_flags;	     /* flags for readdir */
	     pthread_mutex_t dd_lock; /* for thread locking */
	     struct _telldir *dd_td; /* telldir position recording */
     } DIR;

     #define dirfd(dirp)     ((dirp)->dd_fd)

     /* flags for opendir2 */
     #define DTF_HIDEW	     0x0001  /* hide whiteout entries */
     #define DTF_NODUP	     0x0002  /* don't return duplicate names */
     #define DTF_REWIND	     0x0004  /* rewind after reading union stack */
     #define __DTF_READALL   0x0008  /* everything has been read */

     #ifndef NULL
     #define NULL    0
     #endif

     #endif /* _POSIX_SOURCE */

     #endif /* !_DIRENT_H_ */

SEE ALSO
     fs(5), inode(5)

HISTORY
     A dir file format appeared in Version 7 AT&T UNIX.

4.2 Berkeley Distribution	April 19, 1994	     4.2 Berkeley Distribution
[top]

List of man pages available for OpenDarwin

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
...................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net