This is a structure type used to return information about directory
entries. It contains the following fields:
char d_name[]- This is the null-terminated file name component. This is the only
field you can count on in all POSIX systems.
ino_t d_fileno- This is the file serial number. For BSD compatibility, you can also
refer to this member as
d_ino. In the GNU system and most POSIX
systems, for most files this the same as the st_ino member that
stat will return for the file. See File Attributes.
unsigned char d_namlen- This is the length of the file name, not including the terminating null
character. Its type is
unsigned char because that is the integer
type of the appropriate size
unsigned char d_type- This is the type of the file, possibly unknown. The following constants
are defined for its value:
DT_UNKNOWN- The type is unknown. On some systems this is the only value returned.
DT_REG- A regular file.
DT_DIR- A directory.
DT_FIFO- A named pipe, or FIFO. See FIFO Special Files.
DT_SOCK- A local-domain socket.
DT_CHR- A character device.
DT_BLK- A block device.
This member is a BSD extension. The symbol _DIRENT_HAVE_D_TYPE
is defined if this member is available. On systems where it is used, it
corresponds to the file type bits in the st_mode member of
struct statbuf. If the value cannot be determine the member
value is DT_UNKNOWN. These two macros convert between d_type
values and st_mode values:
— Function: int
IFTODT (
mode_t mode)
This returns the d_type value corresponding to mode.
— Function: mode_t
DTTOIF (
int dtype)
This returns the st_mode value corresponding to dtype.
This structure may contain additional members in the future. Their
availability is always announced in the compilation environment by a
macro names _DIRENT_HAVE_D_xxx where xxx is replaced
by the name of the new member. For instance, the member d_reclen
available on some systems is announced through the macro
_DIRENT_HAVE_D_RECLEN.
When a file has multiple names, each name has its own directory entry.
The only way you can tell that the directory entries belong to a
single file is that they have the same value for the d_fileno
field.
File attributes such as size, modification times etc., are part of the
file itself, not of any particular directory entry. See File Attributes.
