STICKY(8) System Manager's Manual STICKY(8)
sticky - executable files with persistent text
While the `sticky bit', mode 01000 (see chmod(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 execution. As long as a copy remains in the swap
area, the original 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 ld(1).
To replace a sticky file that has been used do: (1) Clear the sticky
bit with chmod(1). (2) Execute the old program to flush the swapped
copy. This can be done safely even if others are using it. (3) Over-
write 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 chmod
and chown(2). (4) Set the sticky bit again.
Only the super-user can set the sticky bit.
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.
4th Berkeley Distribution 4 February 1983 STICKY(8)