On June 27, 2005 10:47 am, Stephen Cartwright wrote: > What exactly is the difference between a pid file and a subsystem lock > file? Why do you need both of them? > > Thanks!
A *.pid file is a file that keeps the PID "process id" and that is to record which process to send signals to for various reasons, ie. killing the process (thats not the only reason, but the most common one). What a lock file is for is to signal that a particular resource is in use. Lets say that some program wanted to update /etc/passwd. One way of making sure that two programs are not updating that file is to create a file ie. /var/lock/etc/passwd. When the program is finished updating the file it removes the file in /var/lock. BTW without getting the source I'm not sure how they handle that. If you are curious get the package called util-linux.tar.gz from kernel.org. There are several utilities in that package that have to cope with updating sensitive information like the passwords. Check it out. _______________________________________________ clug-talk mailing list [email protected] http://clug.ca/mailman/listinfo/clug-talk_clug.ca Mailing List Guidelines (http://clug.ca/ml_guidelines.php) **Please remove these lines when replying
