topic Re: checking reference count of directory file open in Operating System - HP-UX

checking reference count of directory file open

danysis — Tue, 03 Feb 2004 22:32:36 GMT

Hi Gurus

I have problem , how can you check , whether one directory is opened by anothere process in
HP-ux

answer expected early

see problem is

I have one directory file /tmp which is opened by one process, when second process tries to open the directory /tmp , it should not allow
How can i check whether directory is opened by other process

cheers
danysis

Re: checking reference count of directory file open

James Murtagh — Tue, 03 Feb 2004 23:00:00 GMT

Hi Danysis,

I think you're looking for the fuser command, i.e. :

# fuser -u /tmp

This will list the process ids - check the manpage for full details. There is also an opensource tool called lsof which is a lot more powerful - its available here :

http://hpux.connect.org.uk/hppd/hpux/Sysadmin/lsof-4.70/

cheers,

James.

Re: checking reference count of directory file open

T G Manikandan — Tue, 03 Feb 2004 23:10:28 GMT

#fuser -cu /tmp

That should list down the processes.

Re: checking reference count of directory file open

danysis — Tue, 03 Feb 2004 23:35:44 GMT

Hi
Thnx for mail

But i want system call which , normal user can use to check , how many instances of directory file is opened by a process

but for fuser commond , you should run as a root , i suppose

My problem is, i want to check whether a directory is opened by another process

Re: checking reference count of directory file open

James Murtagh — Wed, 04 Feb 2004 00:31:58 GMT

I don't think this will be possible without compromising security too much. Is there a call on another system that can do this?

What you could do is write a daemon process that could do the work (through pstat) and have the user's query this, while having it take care of the authentication. A bit of work but if needs must....

- James.

Re: checking reference count of directory file open

Elmar P. Kolkman — Wed, 04 Feb 2004 02:25:50 GMT

You could try to open the file/directory in exclusive mode (O_EXCL option on the open system call) but this will not always work (some NFS implementations ignore it, for instance). But it might help solve your problem: don't count number of open sessions, but block multiple instances of same program to use the same dir/file.

Re: checking reference count of directory file open

Aupee Jean-Francois — Thu, 05 Feb 2004 04:29:47 GMT

Hi danysis,

Try this :

lsof +D /tmp

Best regards