hello David and thank you for your help and your detailed explanation. as I said I used
p :=(PipeableOSProcess command: 'ls') . p output. and it just returns an empty string. Are there other ways to return the output of the terminal ? On Fri, Nov 6, 2015 at 1:57 AM David T. Lewis <le...@mail.msen.com> wrote: > On Thu, Nov 05, 2015 at 09:50:29PM +0000, Dimitris Chloupis wrote: > > So I try to understand how OSProcess work exactly to find why filetree > > seems not able to use it and generating the error I already reported > > earlier. > > > > Using something simple like > > > > OSProcess command:'pwd' > > > > works great , I have the terminal open and I can see the correct return > > value of the command in my terminal but for some reason I can find no > such > > info when I inspect the above example. So how exactly OSProcess returns > the > > output of the terminal ? Is there an instance variable of some sort ? > > Because I tried to inspect it deeply and I found nothing . Can you help > me > > understand how OSProcess work ? Because If I do understand it then I can > > find what the problem is . > > Hi Dimitris, > > The OSProcess and CommandShell packages provide a variety of ways to > create and interact with operating system processes. In the case of > "OSProcess command: 'pwd'" it is starting a new unix shell (/bin/sh, which > on most systems is the Bash shell). Once it starts the shell, it asks > the shell to evaluate the 'pwd' command. In this case, you would see the > output of that 'pwd' command appearing in the terminal window for your > Pharo VM process. > > If you inspect the result of this, you should see an instance of > ExternalUnixOSProcess. This is a proxy that represents the operating > system process that was used to run /bin/sh. It should look something like > this: > > an ExternalUnixOSProcess with pid 10703 on /bin/sh (complete, normal > termination with status 0) > > The exitStatus instance variable of the ExternaUnixProcess should be 0 in > this example, which means only that the shell ran successfully (It does not > tell you exit status of the 'pwd' command in this case, although there are > other ways to do that). > > There are other classes, especially PipeableOSProcess and CommandShell, > that support higher level control of OS processes, with direct connection > of the stdin/stdout/stderr streams to your Smalltalk image. I expect that > filetree would be using these higher level abstractions. > > I don't know if this helps with your problem but maybe it gives you some > ideas. > > Dave > > >
