Deleting a file/directory on startup

[John Dennis]

Till Maas wrote:
> On Mon January 14 2008, Casey Dahlin wrote:
> 
>> The most correct way is to put some content in the lockfile to allow it
>> to be determined if it is valid. Then pm-utils itself can figure it out
>> when its run.
> 
> How can this be done in a bullet-proof way[1]? Also it seems to be a lot more 
> complicated than just to make sure, that the lockdirectory is removed on 
> startup (and there are already a lot of files and directories that are 
> removed on startup by rc.sysinit, so it is more a common way to do it).
> The best way I know would be to be able to identify whether or not a system 
> was rebooted since a file was created, but given there are systems that do 
> not have a hardware clock, I do not know of a way to identify it. Is there, 
> e.g. a file in /proc or /sys that will have a unique content that only 
> changes every time a system is powered up?

Last week I answered and said a standard technique is the use of pid 
files and explained how it works. Is there some reason that approach 
does not give you exactly what you've asked for? The pid can either be 
in a separate pid file or in the lockfile, or both, just be aware of 
potential race conditions if the pid is in more than one file and do the 
operations in the correct order.

-- 
John Dennis <jdennis at redhat.com>