QNX Operating System/Discussion/OSTech/Process information from within application/List of Posts
 
Forum Topic - Process information from within application: (6 Items)
   
Update
Simon Platten
07/22/2011 5:21 AM
post87520
Process information from within application   
I need to be able to determine if an instance of an application is already running.  

The way I would do this on other systems is to look for the application by enumerating the running processes.

I've searched around for ways of doing this in QNX but haven't really found anything that would help.  We are using QNX 
6.3

What I would ideally like to do is as the very first line of my main, check to see if an instance of my application is 
already running and if 'Yes' then display message and abort, if 'No' continue with the execution of the application.

Thank you,
Simon Platten
Pavol Kycina
07/22/2011 5:31 AM
post87521
Re: Process information from within application   
Hello,

Attach some name or prefix, and during the test of uniqueness try to locate that name or prefix.

Regards, PKY
Simon Platten
07/22/2011 6:10 AM
post87522
Re: Process information from within application   
Thanks for the reply, but what does that mean?  Can you point me in the direction of a function to call?
Pavol Kycina
07/22/2011 8:03 AM
post87524
Re: Process information from within application   
Hello,

have a look at this:

http://www.qnx.com/developers/docs/6.3.0SP3/neutrino/lib_ref/n/name_attach.html

In your case something like this cold suffice:

call name_open(your_name)

 if successful {
    exit // another instance already running
 } else {
    call name_attach(your_name)
    // continue with your program
 }

Regards, PKY
Simon Platten
07/22/2011 8:08 AM
post87525
Re: Process information from within application   
Thank you, I will investigate.
Warren Deitch
07/24/2011 8:32 PM
post87550
Re: Process information from within application   
If you do not mind a system() call and interpreting the return code, you could use a 
slay -f -s0 taskName  >/dev/null
The return code will be the number of instances of taskName found.

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