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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd June 5, 1993 29.Dt STICKY 7 30.Os 31.Sh NAME 32.Nm sticky 33.Nd sticky text and append-only directories 34.Sh DESCRIPTION 35A special file mode, called the 36.Em sticky bit 37(mode S_ISTXT), 38is used to indicate special treatment 39for directories. 40It is ignored for regular files. 41See 42.Xr chmod 2 43or 44the file 45.In sys/stat.h 46for an explanation of file modes. 47.Sh STICKY DIRECTORIES 48A directory whose `sticky bit' is set 49becomes an append-only directory, or, more accurately, 50a directory in which the deletion of files is restricted. 51A file in a sticky directory may only be removed or renamed 52by a user if the user has write permission for the directory and 53the user is the owner of the file, the owner of the directory, 54or the super-user. 55This feature is usefully applied to directories such as 56.Pa /tmp 57which must be publicly writable but 58should deny users the license to arbitrarily 59delete or rename each others' files. 60.Pp 61Any user may create a sticky directory. 62See 63.Xr chmod 1 64for details about modifying file modes. 65.Sh HISTORY 66A 67.Nm 68command appeared in 69.At 32v . 70.Sh BUGS 71Neither 72.Xr open 2 73nor 74.Xr mkdir 2 75will create a file with the sticky bit set. 76