how can I make sure only one instance of gkrellm runs

[Antonio Olivares]

--- On Thu, 10/16/08, Patrick O'Callaghan <pocallaghan at gmail.com> wrote:

> From: Patrick O'Callaghan <pocallaghan at gmail.com>
> Subject: Re: how can I make sure only one instance of gkrellm runs
> To: fedora-list at redhat.com
> Date: Thursday, October 16, 2008, 4:08 PM
> On Thu, 2008-10-16 at 15:56 -0700, Antonio Olivares wrote:
> > Dear fellow Fedoreans,
> > 
> > How can I make sure that only one instance of gkrellm
> runs.  When I start one of my machines run several instances
> of gkrellm.  I chose in the configuration run only one, but
> that does not work :(
> > 
> > [olivares at localhost ~]$ whoami 
> > olivares                       
> > [olivares at localhost ~]$ top
> > top - 17:51:33 up  1:36,  4 users,  load average:
> 0.36, 0.50, 0.68
> > Tasks: 130 total,   1 running, 129 sleeping,   0
> stopped,   0 zombie
> > Cpu(s):  4.7%us,  1.0%sy,  0.0%ni, 94.4%id,  0.0%wa, 
> 0.0%hi,  0.0%si,  0.0%st
> > Mem:    773348k total,   712732k used,    60616k free,
>    23792k buffers
> > Swap:  3114416k total,       80k used,  3114336k free,
>   398188k cached
> > 
> >   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM   
> TIME+  COMMAND
> >  2440 root      20   0  216m  63m 7200 S  3.3  8.4  
> 6:00.98 Xorg
> >  2986 olivares  20   0 23088 9832 6528 S  1.0  1.3  
> 0:55.45 gkrellm
> >  3008 olivares  20   0 23056 9868 6556 S  1.0  1.3  
> 0:54.94 gkrellm
> >  2944 olivares  20   0  103m  23m  15m S  0.7  3.1  
> 0:18.71 plasma
> >  2968 olivares  20   0 23088 9832 6528 S  0.7  1.3  
> 0:55.39 gkrellm
> >  2978 olivares  20   0 23088 9828 6528 S  0.7  1.3  
> 0:55.75 gkrellm
> >  2993 olivares  20   0 23088 9836 6528 S  0.7  1.3  
> 0:55.34 gkrellm
> >  3000 olivares  20   0 23088 9832 6528 S  0.7  1.3  
> 0:55.55 gkrellm
> >   554 root      15  -5     0    0    0 S  0.3  0.0  
> 0:04.96 scsi_eh_1
> >  2936 olivares  20   0 60492  16m  12m S  0.3  2.2  
> 0:07.61 kwin
> > 20164 olivares  20   0 73576  15m  11m S  0.3  2.0  
> 0:00.27 konsole
> >     1 root      20   0  2016  848  636 S  0.0  0.1  
> 0:04.38 init
> >     2 root      15  -5     0    0    0 S  0.0  0.0  
> 0:00.00 kthreadd
> > 
> > As you can see there are several gkrellm's running
> :(  
> > 
> > Cameron shared a script with me:
> > 
> > #!/bin/bash
> > #
> > pidfile=$HOME/.grkrellm.pid
> >   if [ -s "$pidfile" ] &&
> pid=$(<"$pidfile") && kill -0
> "$pid" 2>/dev/null
> >   then
> >     echo GKrellM already running, pid=$pid, not
> starting a new one.
> >   else
> >     gkrellm &           # start gkrellm
> >     echo $! >"$pidfile" # save the pid
> >   fi
> > 
> > 
> > And it finds that gkrellm is already running so it
> quits. The script works, but I have to find a way to
> eliminate the extra gkrellm's.  
> > How can I prevent the other gkrellm's and run only
> one?
> 
> 1) You don't say how you run the script.
I don't run the script.  I only run it to check to see if gkrellm is running.  Since gkrellm starts by itself I do not run the script.  What I did before was run
$ killall -9 gkrellm
and then start gkrellm manually so it would run.  But that process is getting boring and tiring.  I would like for it to run by itself only one instance and not all those times that it runs :(
> 2) What does "kill -0" do? "man kill"
> doesn't mention this possibilty.
> 3) The script has an obvious race condition, (i.e. if run
> from several
> places simultaneously, there is a non-zero probability of
> starting more
> than one process). This is because running the process and
> creating the
> pidfile are two separate actions.
> 
> poc
> 
> -- 

The file was set to run automatically when starting one of the two desktops. I ran Gnome for a good while when KDE 4 was coming out, I switched to it to learn more about it, went back to gnome and since Fedora 9 came out and all the wonderful updates came up for KDE 4.1.1 and KDE 4.1.2 came out I have been running it.  It is no longer on 
~/.kde/Autostart/gkrellm or ln -s /usr/bin/gkrellm on it.  

When I log in, gkrellm starts by itself.  I have the don't allow multiple instances of it, but it still runs many copies simultaneously :(

That is the problem.  How can I make sure only one gkrellm runs and get rid of all the others once and for all.

Thank you for helping in trying to resolve this issue.

Regards,

Antonio