4BSD/usr/man/cat8/sticky.8

STICKY(8)           UNIX Programmer's Manual            STICKY(8)



NAME
     sticky - executable files with persistent text

DESCRIPTION
     While the `sticky bit', mode 01000 (see _c_h_m_o_d(2)), is set on
     a sharable executable file, the text of that file will not
     be removed from the system swap area.  Thus the file does
     not have to be fetched from the file system upon each execu-
     tion.  As long as a copy remains in the swap area, the ori-
     ginal text cannot be overwritten in the file system, nor can
     the file be deleted.  (Directory entries can be removed so
     long as one link remains.)

     Sharable files are made by the -n and -z options of _l_d(1).

     To replace a sticky file that has been used do: (1) Clear
     the sticky bit with _c_h_m_o_d(1).  (2) Execute the old program
     to flush the swapped copy.  This can be done safely even if
     others are using it.  (3) Overwrite the sticky file.  If the
     file is being executed by any process, writing will be
     prevented; it suffices to simply remove the file and then
     rewrite it, being careful to reset the owner and mode with
     _c_h_m_o_d and _c_h_o_w_n(2).  (4) Set the sticky bit again.

     Only the super-user can set the sticky bit.

BUGS
     Are self-evident.

     Is largely unnecessary on the VAX; matters only for large
     programs that will page heavily to start, since text pages
     are normally cached incore as long as possible after all
     instances of a text image exit.






















Printed 11/10/80                                                1