STICKY(8) BSD System Manager's Manual STICKY(8)

NAME
     ssttiicckkyy - sticky text and append-only directories

DESCRIPTION
     A special file mode, called the sticky bit (mode SISVTX), is used to
     indicate special treatment for shareable executable files and directo-
     ries.  See chmod(2) or the file /usr/include/sys/stat.h for an explana-
     tion of file modes.

STICKY TEXT EXECUTABLE FILES
     The sticky bit has no effect on executable files. All optimization on
     whether text images remain resident in memory is handled by the kernel's
     virtual memory system.

SSTTIICCKKYY DDIIRREECCTTOORRIIEESS
     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 removed 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.

BUGS
     Neither open(2) nor mkdir(2) will create a file with the sticky bit set.

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

4th Berkeley Distribution        June 5, 1993        4th Berkeley Distribution