1.\" Copyright (c) 1980, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)sticky.8 8.1 (Berkeley) 6/5/93 33.\" $FreeBSD: src/share/man/man8/sticky.8,v 1.7.2.1 2001/08/17 13:08:50 ru Exp $ 34.\" $DragonFly: src/share/man/man8/sticky.8,v 1.2 2003/06/17 04:37:01 dillon Exp $ 35.\" 36.Dd June 5, 1993 37.Dt STICKY 8 38.Os 39.Sh NAME 40.Nm sticky 41.Nd sticky text and append-only directories 42.Sh DESCRIPTION 43A special file mode, called the 44.Em sticky bit 45(mode S_ISVTX), 46is used to indicate special treatment 47for directories. 48It is ignored for regular files. 49See 50.Xr chmod 2 51or 52the file 53.Pa /usr/include/sys/stat.h 54for an explanation of file modes. 55.Sh STICKY DIRECTORIES 56A directory whose `sticky bit' is set 57becomes an append-only directory, or, more accurately, 58a directory in which the deletion of files is restricted. 59A file in a sticky directory may only be removed or renamed 60by a user if the user has write permission for the directory and 61the user is the owner of the file, the owner of the directory, 62or the super-user. 63This feature is usefully applied to directories such as 64.Pa /tmp 65which must be publicly writable but 66should deny users the license to arbitrarily 67delete or rename each others' files. 68.Pp 69Any user may create a sticky directory. 70See 71.Xr chmod 1 72for details about modifying file modes. 73.Sh BUGS 74Neither 75.Xr open 2 76nor 77.Xr mkdir 2 78will create a file with the sticky bit set. 79.Sh HISTORY 80A 81.Nm 82command appeared in 83.At 32v . 84