VOP_READDIR(9) read contents of a directory

SYNOPSIS

In sys/param.h In sys/dirent.h In sys/vnode.h Ft int Fn VOP_READDIR struct vnode *vp struct uio *uio struct ucred *cred int *eofflag int *ncookies u_long **cookies

DESCRIPTION

Read directory entries.

Fa vp
The vnode of the directory.
Fa uio
Where to read the directory contents.
Fa cred
The caller's credentials.
Fa eofflag
Return end of file status ( NULL if not wanted).
Fa ncookies
Number of directory cookies generated for NFS ( NULL if not wanted).
Fa cookies
Directory seek cookies generated for NFS ( NULL if not wanted).

The directory contents are read into Vt struct dirent structures. If the on-disc data structures differ from this then they should be translated.

LOCKS

The directory should be locked on entry and will still be locked on exit.

RETURN VALUES

Zero is returned on success, otherwise an error code is returned.

If this is called from the NFS server, the extra arguments Fa eofflag , Fa ncookies and Fa cookies are given. The value of Fa *eofflag should be set to TRUE if the end of the directory is reached while reading. The directory seek cookies are returned to the NFS client and may be used later to restart a directory read part way through the directory. There should be one cookie returned per directory entry. The value of the cookie should be the offset within the directory where the on-disc version of the appropriate directory entry starts. Memory for the cookies should be allocated using:

        ...;
        *ncookies = number of entries read;
        *cookies = malloc(*ncookies * sizeof(u_long), M_TEMP, M_WAITOK);

ERRORS

Bq Er EINVAL
An attempt was made to read from an illegal offset in the directory.
Bq Er EIO
A read error occurred while reading the directory.

AUTHORS

This manual page was written by An Doug Rabson .