NAME
getdirentries() — get entries from a directory in a file-system-independent format
SYNOPSIS
#include <ndir.h>
int getdirentries(
int fildes,
struct direct *buf,
size_t nbytes,
off_t *basep
);
DESCRIPTION
The
getdirentries()
system call and the
<ndir.h>
header file have been obsoleted starting from HP-UX 10.30
by the functions described in
directory(3C).
getdirentries()
will not be supported for 64-bit applications.
The
getdirentries()
system call places directory entries
from the directory referenced by the file descriptor
fildes
into the buffer pointed to by
buf,
in a file-system-independent format.
Up to
nbytes
of data are transferred.
nbytes
must be greater than or equal to the block size associated with the
file; see
st_blksize
in
stat(2).
(Smaller block sizes can cause errors on certain file systems.)
nbytes
must be less than or equal to 65536 (64K).
The data in the buffer consists of a series of
direct
structures, each containing the following entries:
unsigned long d_fileno;
unsigned short d_reclen;
unsigned short d_namlen;
char d_name[MAXNAMLEN + 1];
The
d_fileno
entry is a number unique for each distinct file in the file system.
Files linked by hard links (see
link(2))
have the same
d_fileno.
The
d_reclen
entry identifies the length, in bytes, of the directory record.
The
d_name
entry contains a null-terminated file name.
The
d_namlen
entry specifies the length of the file name.
Thus the actual size of
d_name
can vary from 2 to
MAXNAMLEN
+ 1.
Note that the
direct
structures in the buffer are not necessarily tightly packed.
The
d_reclen
entry must be used as an offset from the beginning of a
direct
structure to the next structure, if any.
The return value of the system call
is the actual number of bytes transferred.
The current position pointer associated with
fildes
is set to point to the next block of entries.
The pointer is not necessarily incremented
by the number of bytes returned by
getdirentries().
If the value returned is zero, the end of the directory has been reached.
The current position pointer is set and retrieved by
lseek();
see
lseek(2).
getdirentries()
writes the position of the block read into the location pointed to by
basep.
The current position pointer can be set safely
only to a value previously returned by
lseek(),
to a value previously returned in the location pointed to by
basep,
or to zero.
Any other manipulation of the position pointer causes undefined results.
RETURN VALUE
getdirentries()
returns the following values:
- n
Successful completion.
n
is the number of bytes actually transferred.
- -1
Failure.
errno
is set to indicate the error.
ERRORS
If
getdirentries()
fails,
errno
is set to one of the following values:
- [EBADF]
fildes
is not a valid file descriptor open for reading.
- [EFAULT]
Either
buf
or
basep
points outside the allocated address space.
- [EINTR]
A read from a slow device was interrupted by the delivery of a signal
before any data arrived.
- [EINVAL]
nbytes
is greater than the size of the
direct
structure pointed to by
buf.
- [EINVAL]
nbytes
is greater than 65536 or is smaller than the size of a single
directory entry.
- [EIO]
An I/O error occurred while reading from or writing to the file system.
AUTHOR
getdirentries()
was developed by Sun Microsystems, Inc.
