>>>>> "JM" == John Macdonald <[EMAIL PROTECTED]> writes:
JM> On Tue, Feb 21, 2006 at 03:25:08PM -0500, Uri Guttman wrote: >> another issue is should you keep a handle open between tail polls or >> open it fresh each time? since my code checks the inode number, opening >> each time makes more sense. JM> Even if you didn't do that to force the inode change, you JM> can still tell whether the file has been cycled (even it the JM> new one is back to the same size) by seeking backwards a bit JM> and re-reading the last text you pulled in and comparing to JM> make sure it is still the same. (This does assume that log JM> file entries have a timestamp or some other component that JM> will make an adequately long text segment certain to never be JM> exactly duplicated in a subsequent log entry.) any assumptions mean that it is still 'possible' to not detect changes in a log file. i wasn't saying it is a real world problem but just that it isn't bulletproof. it is like a race condition that can rarely happen. JM> Of course, detecting that a log switch of some sort has occurred JM> doesn't ensure that you will be able to tell if more than one JM> has occurred "very quickly" (from your frame of reference - JM> that might mean that your tailing program got paused for a JM> long time instead). well, most tailing doesn't care about how much has changed. tailing just wants to find and return the appended text. whether it returns large chunks or many lines isn't a function of the log file but of the tailing code. uri -- Uri Guttman ------ [EMAIL PROTECTED] -------- http://www.stemsystems.com --Perl Consulting, Stem Development, Systems Architecture, Design and Coding- Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org _______________________________________________ Boston-pm mailing list [email protected] http://mail.pm.org/mailman/listinfo/boston-pm
