3 .\" Copyright (c) 1996 Doug Rabson
5 .\" All rights reserved.
7 .\" This program is free software.
9 .\" Redistribution and use in source and binary forms, with or without
10 .\" modification, are permitted provided that the following conditions
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13 .\" notice, this list of conditions and the following disclaimer.
14 .\" 2. Redistributions in binary form must reproduce the above copyright
15 .\" notice, this list of conditions and the following disclaimer in the
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18 .\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
19 .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 .\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
22 .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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29 .\" $FreeBSD: src/share/man/man9/VOP_READDIR.9,v 1.6.2.1 2001/12/17 11:30:18 ru Exp $
30 .\" $DragonFly: src/share/man/man9/VOP_READDIR.9,v 1.3 2003/07/27 05:36:06 hmp Exp $
37 .Nd read contents of a directory
43 .Fn VOP_READDIR "struct vnode *vp" "struct uio *uio" "struct ucred *cred" "int *eofflag" "int *ncookies" "u_long **cookies"
45 Read directory entries.
46 .Bl -tag -width ncookies
48 the vnode of the directory
50 where to read the directory contents
52 the caller's credentials
54 return end of file status (NULL if not wanted)
56 number of directory cookies generated for NFS (NULL if not wanted)
58 directory seek cookies generated for NFS (NULL if not wanted)
60 The directory contents are read into
62 structures. If the on-disc data structures differ from this then they
65 The directory should be locked on entry and will still be locked on exit.
67 Zero is returned on success, otherwise an error code is returned.
69 If this is called from the NFS server, the extra arguments
77 should be set to TRUE if the end of the directory is reached while
79 The directory seek cookies are returned to the NFS client and may be used
80 later to restart a directory read part way through the directory.
81 There should be one cookie returned per directory entry. The value of
82 the cookie should be the offset within the directory where the on-disc
83 version of the appropriate directory entry starts.
84 Memory for the cookies should be allocated using:
88 *ncookies = number of entries read;
90 malloc(*ncookies * sizeof(u_int), M_TEMP, M_WAITOK);
95 vop_readdir(struct vnode *vp, struct uio *uio, struct ucred *cred,
96 int *eofflag, int *ncookies, u_int **cookies)
102 * Remember the original offset to use later in generating cookies.
104 off = uio->uio_offset;
107 * Read directory contents starting at uio->uio_offset into buffer
112 if (!error && ncookies != NULL) {
113 struct dirent *dpStart;
114 struct dirent *dpEnd;
120 if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
121 panic("vop_readdir: unexpected uio from NFS server");
124 * Parse the stuff just read into the uio.
126 dpStart = (struct dirent *)
127 (uio->uio_iov->iov_base - (uio->uio_offset - off));
128 dpEnd = (struct dirent *) uio->uio_iov->iov_base;
131 * Count number of entries.
133 for (dp = dpStart, count = 0;
135 dp = (struct dirent *)((caddr_t) dp + dp->d_reclen))
138 cookiebuf = (u_int *) malloc(count * sizeof(u_int), M_TEMP, M_WAITOK);
139 for (dp = dpStart; cookiep = cookiebuf;
141 dp = (struct dirent *)((caddr_t) dp + dp->d_reclen)) {
143 *cookiep++ = (u_int) off;
146 *cookies = cookiebuf;
149 if (eofflag && uio->uio_offset is past the end of the directory) {
159 attempt to read from an illegal offset in the directory
161 a read error occurred while reading the directory
166 This man page was written by