xref: /freebsd/share/man/man9/VOP_READDIR.9 (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
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3.\" Copyright (c) 1996 Doug Rabson
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29.\" $FreeBSD$
30.\"
31.Dd July 24, 1996
32.Dt VOP_READDIR 9
33.Os
34.Sh NAME
35.Nm VOP_READDIR
36.Nd read contents of a directory
37.Sh SYNOPSIS
38.In sys/param.h
39.In sys/dirent.h
40.In sys/vnode.h
41.Ft int
42.Fn VOP_READDIR "struct vnode *vp" "struct uio *uio" "struct ucred *cred" "int *eofflag" "int *ncookies" "u_long **cookies"
43.Sh DESCRIPTION
44Read directory entries.
45.Bl -tag -width ncookies
46.It Fa vp
47The vnode of the directory.
48.It Fa uio
49Where to read the directory contents.
50.It Fa cred
51The caller's credentials.
52.It Fa eofflag
53Return end of file status
54.Dv ( NULL
55if not wanted).
56.It Fa ncookies
57Number of directory cookies generated for NFS
58.Dv ( NULL
59if not wanted).
60.It Fa cookies
61Directory seek cookies generated for NFS
62.Dv ( NULL
63if not wanted).
64.El
65The directory contents are read into
66.Vt struct dirent
67structures.
68If the on-disc data structures differ from this then they
69should be translated.
70.Sh LOCKS
71The directory should be locked on entry and will still be locked on exit.
72.Sh RETURN VALUES
73Zero is returned on success, otherwise an error code is returned.
74.Pp
75If this is called from the NFS server, the extra arguments
76.Fa eofflag ,
77.Fa ncookies
78and
79.Fa cookies
80are given.
81The value of
82.Fa *eofflag
83should be set to TRUE if the end of the directory is reached while
84reading.
85The directory seek cookies are returned to the NFS client and may be used
86later to restart a directory read part way through the directory.
87There should be one cookie returned per directory entry.
88The value of
89the cookie should be the offset within the directory where the on-disc
90version of the appropriate directory entry starts.
91Memory for the cookies should be allocated using:
92.Bd -literal
93	...;
94	*ncookies = number of entries read;
95	*cookies = malloc(*ncookies * sizeof(u_long), M_TEMP, M_WAITOK);
96.Ed
97.Sh ERRORS
98.Bl -tag -width Er
99.It Bq Er EINVAL
100An attempt was made to read from an illegal offset in the directory.
101.It Bq Er EIO
102A read error occurred while reading the directory.
103.El
104.Sh SEE ALSO
105.Xr vnode 9
106.Sh AUTHORS
107This manual page was written by
108.An Doug Rabson .
109