Proper way to use many PipeableOSProcesses ?

> Hi,
>
> I need to pass a bunch of strings through a unix command. I'm using
> this repeatedly:
>
> cat := (PipeableOSProcess command: '/bin/cat')
> nextPutAll: aString;
> close.
> cat output "do something with that"
>
> After roughly 120 iterations, I get an error "cannot create OS pipe"
> from ExternalPipe>>makePipe, and all subsequent PipeableOSProcesses do
> that until I relaunch the image. Did I miss something? should I
> flush/wait/finalize something?
>

> Hi Damien,
>
> The #close on PipeableOSProcess will only close the input pipe (the
> OS pipe that connects Squeak to the stdin of the external process).
> It leaves the output and error pipes open (I guess that #close was a
> poor selector name, since it implies "closing" the whole thing). As
> a result, you will eventually run out of file handles for the Squeak
> VM process, and that is why you get the error.
>
> You can just add a #closePipes when you have finished reading the
> process output, and this should clean things up properly:
>
>   outputs := OrderedCollection new.
>   1000 timesRepeat:
>   [cat := PipeableOSProcess command: '/bin/cat'.
>   cat nextPutAll: 'fooBarBaz'; close.
>   outputs add: cat output.
>   cat closePipes].
>   outputs inspect
>
> If you are using an operating system with a /proc file system (ie Linux),
> it is helpful to look at /proc/<squeakpid>/fd/* to see the open file
> descriptors. If you are accumulating file descriptors in that directory,
> then you have a leak such at this one.
>
> Dave
>
> On Sun, Dec 09, 2007 at 07:22:31PM +0100, Damien Pollet wrote:
> > Hi,
> >
> > I need to pass a bunch of strings through a unix command. I'm using
> > this repeatedly:
> >
> > cat := (PipeableOSProcess command: '/bin/cat')
> >       nextPutAll: aString;
> >       close.
> > cat output "do something with that"
> >
> > After roughly 120 iterations, I get an error "cannot create OS pipe"
> > from ExternalPipe>>makePipe, and all subsequent PipeableOSProcesses do
> > that until I relaunch the image. Did I miss something? should I
> > flush/wait/finalize something?
> >
>
>