STICKY(7) Standards, Environments, and Macros STICKY(7)

NAME

sticky - mark files for special treatment

DESCRIPTION

The sticky bit (file mode bit 01000, see chmod(2)) is used to
indicate special treatment of certain files and directories. A
directory for which the sticky bit is set restricts deletion of files
it contains. A file in a sticky directory can only be removed or
renamed by a user who has write permission on the directory, and
either owns the file, owns the directory, has write permission on the
file, or is a privileged user. Setting the sticky bit is useful for
directories such as /tmp, which must be publicly writable but should
deny users permission to arbitrarily delete or rename the files of
others.


If the sticky bit is set on a regular file and no execute bits are
set, the system's page cache will not be used to hold the file's
data. This bit is normally set on swap files of diskless clients so
that accesses to these files do not flush more valuable data from the
system's cache. Moreover, by default such files are treated as swap
files, whose inode modification times may not necessarily be
correctly recorded on permanent storage.


Any user may create a sticky directory. See chmod for details about
modifying file modes.

SEE ALSO

chmod(1), chmod(2), chown(2), mkdir(2), rename(2), unlink(2)

BUGS

The mkdir(2) function will not create a directory with the sticky bit
set.

August 1, 2002 STICKY(7)