NAME
getdents —
get directory entries in a file system
independent format
LIBRARY
library “libc”
SYNOPSIS
#include
<dirent.h>
int
getdents(int
fd, char *buf,
size_t nbytes);
DESCRIPTION
getdents()
reads directory entries from the directory referenced by the file descriptor
fd into the buffer pointed to by
buf, in a file system 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 file systems may not support
getdents() with buffers smaller than this size.
The data in the buffer is a series of dirent structures:
struct dirent {
ino_t d_fileno; /* file number of entry */
uint16_t d_reclen; /* length of this record */
uint16_t d_namlen; /* length of d_name */
uint8_t d_type; /* file type, see below */
char d_name[MAXNAMLEN + 1];
};
The structure is described in dirent(3).
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.
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
getdents().
A value of zero is returned when the end of the directory has been
reached.
The current position pointer may be set and retrieved by lseek(2). The current position pointer should only be set to a value returned by lseek(2), or zero.
RETURN VALUES
If successful, the number of bytes actually transferred is returned. Otherwise, -1 is returned and the global variable errno is set to indicate the error.
ERRORS
getdents() will fail if:
- [
EBADF] - fd is not a valid file descriptor open for reading.
- [
EFAULT] - buf points outside the allocated address space.
- [
EINVAL] - A directory was being read on NFS, but it was modified on the server while it was being read.
- [
EIO] - An I/O error occurred while reading from or writing to the file system.
SEE ALSO
HISTORY
The getdents() function first appeared in
NetBSD 1.3.