NAME
dirent.h - format of directory entries
SYNOPSIS
#include <dirent.h>
DESCRIPTION
The internal format of directories is unspecified.
The <dirent.h> header shall define the following type:
DIR A type representing a directory stream.
It shall also define the structure dirent which shall include the
following members:
ino_t d_ino File serial number.
char d_name[] Name of entry.
The type ino_t shall be defined as described in <sys/types.h> .
The character array d_name is of unspecified size, but the number of
bytes preceding the terminating null byte shall not exceed {NAME_MAX}.
The following shall be declared as functions and may also be defined as
macros. Function prototypes shall be provided.
int closedir(DIR *);
DIR *opendir(const char *);
struct dirent *readdir(DIR *);
int readdir_r(DIR *restrict, struct dirent *restrict,
struct dirent **restrict);
void rewinddir(DIR *);
void seekdir(DIR *, long);
long telldir(DIR *);
The following sections are informative.
APPLICATION USAGE
None.
RATIONALE
Information similar to that in the <dirent.h> header is contained in a
file <sys/dir.h> in 4.2 BSD and 4.3 BSD. The equivalent in these
implementations of struct dirent from this volume of
IEEE Std 1003.1-2001 is struct direct. The filename was changed because
the name <sys/dir.h> was also used in earlier implementations to refer
to definitions related to the older access method; this produced name
conflicts. The name of the structure was changed because this volume of
IEEE Std 1003.1-2001 does not completely define what is in the
structure, so it could be different on some implementations from struct
direct.
The name of an array of char of an unspecified size should not be used
as an lvalue. Use of:
sizeof(d_name)
is incorrect; use:
strlen(d_name)
instead.
The array of char d_name is not a fixed size. Implementations may need
to declare struct dirent with an array size for d_name of 1, but the
actual number of characters provided matches (or only slightly exceeds)
the length of the filename.
FUTURE DIRECTIONS
None.
SEE ALSO
<sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001,
closedir(), opendir(), readdir(), readdir_r(), rewinddir(), seekdir(),
telldir()
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .