sticky(8)

NAME

sticky - sticky text and append-only directories

DESCRIPTION

A special file mode, called the sticky bit (mode S_ISTXT),

is used to
indicate special treatment for directories. It is ignored

for regular
files. See chmod(2) or the file #include <sys/stat.h> for an explanation of file modes.

STICKY DIRECTORIES

A directory whose `sticky bit' is set becomes an append-only

directory,
or, more accurately, a directory in which the deletion of

files is
restricted. A file in a sticky directory may only be re

moved or renamed
by a user if the user has write permission for the directory

and the user
is the owner of the file, the owner of the directory, or the

super-user.
This feature is usefully applied to directories such as /tmp

which must
be publicly writable but should deny users the license to

arbitrarily
delete or rename each others' files.

Any user may create a sticky directory. See chmod(1) for

details about
modifying file modes.

HISTORY

A sticky command appeared in Version 32V AT&T UNIX.

BUGS

Neither open(2) nor mkdir(2) will create a file with the

sticky bit set.

BSD June 5, 1993

BSD