On 04/08/2013 00:20, kpn...@pobox.com wrote:
On Sun, Aug 04, 2013 at 12:11:21AM +0100, Frank Leonhardt wrote:
The answer isn't (AFAIK) newsyslog
As a one-off, I need to archive an old log file - say httpd-access.log -
while its still open. I don't want this to happen automatically and I
don't want to set up newsyslog or anything like that. And I really don't
want to mess about with signals to whatever is writing to the file, even
assuming the writer could respond to them. I can't just rename the file
as it's open for writing, and there would also be a good chance that
something will be added to the file while it's being compressed.
What I actually do is:
cp httpd-access.log httpd-access.log-03-Aug-13 && :> httpd-access.log &&
bzip2 httpd-access.log-03-Aug-13
Data might be lost here as something may be added between the cp being
completed and the file being truncated. It's not the end of the world if
this happens, but is there a better way? I could always shut down Apache
for the duration, but I don't want to do that either, so in this case
I'm happy to take the risk (it's not like I'm likely to miss anything
that important).
I don't know if this can be relied on as a POSIX thing, but the cp
command simply(!) issues read() and write() calls until read() fails to
get any more bytes, so if data is being appended to the file after cp is
started it'll still be copied. Therefore the window where stuff could be
written after the copy but before the truncation is shortened, but extant.
So what's the magic utility I don't know about?
How about cronolog? I use it with Apache where Apache logs to cronolog
and cronolog handles the rotating of the logs. No signals. No races.
It even makes a symlink pointing at the newest log file.
It doesn't seem to have a way to compress logs, but you could probably
script up something that wakes up every so often and compresses files
if a newer file exists.
Thanks for the suggestion - I wasn't aware of cronolog. Unfortunately it
doesn't work on existing log files, only stuff piped to it from the
start, so it won't help here. I can see it being very handy in other
situations though. httpd-access.log was just an example of such a file,
but I'm looking for a general solution.
_______________________________________________
freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
