truncating an open (locked) file

[Gregory Kemnitz]

In article <269 at sawmill.UUCP>, rjk at sawmill.UUCP (Richard Kuhns) writes:
< 
< [stuff deleted] 

< Don't close(2) the second file descriptor!  If you close *either* file
< descriptor, the lock goes away.  At least, it does on a 3B1 running 3.51 --
< is this behaviour standard?

Yes.  close() will free any locks on files.

< 
< So now, I have a slight variation of my original question:  Does anyone
< have a portable way to truncate (to size 0) an open file, which both
< maintains an existing lock on the file and doesn't waste a file
< descriptor?
< 

No.  There is not.  Only hope:  there is a truncate() and ftruncate() call
in POSIX, so there will be one in Sys V.4.

-- 
----------------------------------+--------------------------------------
Greg Kemnitz                      |  "He who does not understand baseball
kemnitz at Convergent.COM            |   will never understand America"
                                  |  --Tocqueville