NAME
getdirentries —
get directory entries
in a filesystem independent format
SYNOPSIS
#include <dirent.h>
int
getdirentries(
int
fd,
char *buf,
int nbytes,
long *basep);
DESCRIPTION
This interface is
provided for compatibility only and has been obsoleted by
getdents(2).
getdirentries() 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
getdirentries() with buffers smaller than this size.
The data in the buffer is a series of
dirent structures each
containing the following entries:
unsigned long d_fileno;
unsigned short d_reclen;
unsigned short d_namlen;
char d_name[MAXNAMELEN + 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. If
d_fileno is zero, the
entry refers to a deleted file.
The
d_reclen entry is the length, in bytes, of the
directory record.
The
d_namlen entry specifies the length of the file name
excluding the null byte. Thus the actual size of
d_name
may vary from 1 to
MAXNAMELEN
+ 1.
The
d_name entry contains a null 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.
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
getdirentries(). A value of zero is returned when the end of
the directory has been reached.
getdirentries() writes the position of the block read into the
location pointed to by
basep. Alternatively, 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), a value returned in the
location pointed to by
basep, 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
getdirentries() will fail if:
-
-
- [
EBADF
]
- fd is not a valid file descriptor
open for reading.
-
-
- [
EFAULT
]
- Either buf or
basep point outside the allocated address
space.
-
-
- [
EIO
]
- An I/O error occurred while reading from or writing to the
file system.
SEE ALSO
lseek(2),
open(2)
HISTORY
The
getdirentries() function first appeared in
4.4BSD.