check instace already running...

[Fabio Pliger]

Hi,
is it possibile, in python, to check for an already running instance of an
application?
My problem is that, if my program i running and the user relaunch it, i
don't want to open a new instance and have to instances of the same program
running togheter...
Can someone help me on this?
Fabio P.

[Sidharth Kuruvila]

Re: check instace already running...

I haven't tested this. There is probably a better way of doing this
looking at process information. I use a lock file to mark that the
program is already running. The problem is that for an abrupt shutdown
the file might not be removed.

import atexit
if os.path.exists( lockfile):
print "there is an instance already running"
else:
file(lockfile, "w").close( )
atexit.register (lambda:os.remo ve(lockfile))

//Your code here

On Apr 9, 2005 2:32 PM, Sidharth Kuruvila <sidharth.kuruv ila@gmail.com> wrote:[color=blue]
> I haven't tested this. There is probably a better way of doing this
> looking at process information. I use a lock file to mark that the
> program is already running. The problem is that for an abrupt shutdown
> the file might not be removed.
>
> import atexit
> if os.path.exists( lockfile):
> print "there is an instance already running"
> else:
> file(lockfile, "w").close( )
> atexit.register (lambda:os.remo ve(lockfile))
>
> //Your code here
>
> On Apr 9, 2005 2:01 PM, Fabio Pliger <fabio.pliger@s iavr.it> wrote:[color=green]
> > Hi,
> > is it possibile, in python, to check for an already running instance of an
> > application?
> > My problem is that, if my program i running and the user relaunch it, i
> > don't want to open a new instance and have to instances of the same program
> > running togheter...
> > Can someone help me on this?
> > Fabio P.
> >
> > --
> > http://mail.python.org/mailman/listinfo/python-list
> >[/color]
>
> --
> http://blogs.applibase.net/sidharth
>[/color]


--

http://blogs.applibase.net/sidharth

[Aldric L'Hernault]

Re: check instace already running...

Sidharth Kuruvila a écrit :[color=blue]
> I haven't tested this. There is probably a better way of doing this
> looking at process information. I use a lock file to mark that the
> program is already running. The problem is that for an abrupt shutdown
> the file might not be removed.[/color]

To enhance your check, just write the PID into the file.
On startup, if file exists, you may check that the process
who has written it is still alive.

Aldric L.

[Fabio Pliger]

Re: check instace already running...

"Aldric L'Hernault" <aldric.lhernau lt@free.fr.net^ W> ha scritto nel
messaggio news:42590357$0 $28646$636a15ce @news.free.fr.. .[color=blue]
> Sidharth Kuruvila a écrit :[color=green]
> > I haven't tested this. There is probably a better way of doing this
> > looking at process information. I use a lock file to mark that the
> > program is already running. The problem is that for an abrupt shutdown
> > the file might not be removed.[/color]
>
> To enhance your check, just write the PID into the file.
> On startup, if file exists, you may check that the process
> who has written it is still alive.
>
> Aldric L.[/color]


Yeah, but how can i retrieve my PID number?And how do i check if the process
who has written the file is still alive?If there a way to have the list of
the precesses running?