getdirentries(2)getdirentries(2)Namegetdirentries - gets directory entries in a generic directory format
cc = getdirentries(fd, buf, nbytes, basep)
int cc, fd;
The system call puts directory entries from the directory referenced by
the file descriptor fd into the buffer pointed to by buf, in a generic
directory format. Up to nbytes of data are transferred. The nbytes of
data must be greater than or equal to the block size associated with
the file. For further information, see Sizes less than nbytes can
cause errors on certain file systems.
The data returned in the buffer is a series of direct structures, each
containing the following entries:
unsigned long d_ino;
unsigned short d_reclen;
unsigned short d_namlen;
char d_name[MAXNAMLEN + 1];
The d_ino entry is a number that is unique for each distinct file in
the file system. Files that are linked by hard links have the same
d_ino . For further information, see The d_reclen entry is the length,
in bytes, of the directory record. The d_namlen entry specifies the
length of the file name. The d_name entry contains a null-terminated
file name. Thus, the actual size of d_name can vary from 2 to MAX‐
NAMLEN + 1.
The generic directory structures are not necessarily tightly packed.
The d_reclen entry may be used as an offset from the beginning of a
direct structure to the next structure, if any.
Upon return, 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 is not necessarily incremented by the
number of bytes returned by If the value returned is zero, the end of
the directory has been reached. The current position pointer may be
set and retrieved by The system call writes the position of the block
read into the location pointed to by basep. It is not safe to set the
current position pointer to any value other than a value previously
returned by or a value previously returned in the location pointed to
by basep or zero.
If successful, the number of bytes actually transferred is returned.
Otherwise, a -1 is returned and the global variable errno is set to
indicate the error.
The system call fails under the following conditions:
EBADF The fd is not a valid file descriptor open for reading.
ENOTDIR The fd is not a directory.
EFAULT Either buf or basep points outside the allocated address
EIO While reading from or writing to the file system, an I/O
EINTR A read from a slow device was interrupted by the deliv‐
ery of a signal before any data arrived.
EPERM The user does not have read permission in the directory.
The system call is not the suggested interface for read‐
ing directories. The and routines offer a standard
interface. See the reference page for information on
See Alsoclose(2), link(2), lseek(2), open(2), stat(2), directory(3)getdirentries(2)