|GETDENTS(2)||System Calls Manual||GETDENTS(2)|
getdents — get
directory entries in a filesystem independent format
fd, void *buf,
getdents() reads directory entries from
the directory referenced by the file descriptor fd
into the buffer pointed to by buf, in a filesystem
independent format. Up to nbytes of data will be
transferred. nbytes must be greater than or equal to
the block size associated with the file (see
stat(2)). Some filesystems may not support
getdents() with buffers smaller than this size.
The data in the buffer is a series of dirent structures each containing at least the following entries:
ino_t d_fileno; off_t d_off; u_int16_t d_reclen; u_int8_t d_type; u_int8_t d_namlen; char d_name[MAXNAMLEN + 1]; /* see below */
The d_fileno entry is a number which is unique for each distinct file in the filesystem. Files that are linked by hard links (see link(2)) have the same d_fileno. The d_off entry is the file offset of the next entry. The d_reclen entry is the length, in bytes, of the directory record.
The d_type is the type of file, where the
following are possible types:
The d_namlen entry specifies the length of
the file name excluding the NUL byte. Thus the actual size of
d_name may vary from 1 to
MAXNAMLEN + 1.
The d_name entry contains a NUL-terminated file name.
Entries may be separated by extra space. The d_reclen entry may be used as an offset from the start of a dirent structure to the next structure, if any.
Invalid entries with d_fileno set to 0 may be returned among regular entries.
The actual number of bytes transferred is returned. The current
position pointer associated with fd is set to point to
the next block of entries. The pointer may not advance by the number of
bytes returned by
If successful, the number of bytes actually transferred is returned. A value of zero is returned when the end of the directory has been reached. Otherwise, -1 is returned and the global variable errno is set to indicate the error.
getdents() will fail if:
getdents() call is not a portable
interface and should not be used directly by applications. Use
getdirentries() function first
appeared in 4.4BSD. In OpenBSD
5.5 the d_off entry was added to
struct dirent and
getdirentries() was replaced with
|December 16, 2014||OpenBSD-current|