sticky(5)

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 direc-
     tories. A directory for which the sticky  bit  is  set  res-
     tricts  deletion  of  files it contains.  A file in a sticky
     directory may only be removed or renamed by a user  who  has
     write permission on the directory, and either owns the file,
     owns the directory, or is the super-user. This 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.

FILES

     /tmp

SEE ALSO

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

BUGS

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