Good morning Christian! I am experimenting with the ShellMBS class as a replacement to the xojo shell I’m using now as I need to be able to set some environment variables which your class supports and theirs doesn’t. I’ve run into a couple of odd issues I hope you can shed some light on. This is a MacOS only app at the moment but I’m trying not to have to use NSTask as I’d like to be able to build for linux in the future.
This app starts many helper apps as “plugins” which then communicate through a socket to the main app. Very little communication is done through the stdin/out pipes but I still read them and log anything that comes up as that is where some basic errors show up while developing the helpers. It would be helpful to have a note in the documentation that shellMBS uses the folderitem.nativePath property and not the shell path as the xojo shell does. This means it works fine up until you try to launch something that has an escaped space in the command line at which point it fails with an NSException that has no other information associated with it making it tricky to pin down ;) Unescaped spaces or other characters seem to work fine in the path. Took me a while to figure out why it worked in one place but not in another ;) This is also true of arguments being passed. They can contain spaces but if you add slashes to them then it does not work. Additionally if parameters are passed with quotes around them as one sometimes does with the xojo shell those quotes are still there when it’s passed to the child process unlike with the xojo shell. None of those things are a problem but I just didn’t realize that going in ;) My first issue is that I’m unable to read anything from stderr. If I see that the availableBytesError has some data in it during the DataAvailable event and attempt to read it while the shell process is still running it hangs the app completely and must be force quit. If I try to read it after the process as quit when the data available event fires prior to the completed event then I can at least call readError without it hanging, but none of the data is returned, the string is always empty even if availableBytesError claims there is some output there. My second issue is a bit stranger ;) If the parent app crashes, or needs to be force quit, the shell processes that have sockets open never close them. The remote devices they are connected to never realize they have gone away and if they are listening sockets those are never released. Even hours later they are still not available. The processes themselves are not stuck running, or at least they don’t show up in the Activity Monitor. When using the regular Xojo shell class if the program crashes it can be restarted immediately and everything reconnects just as if the sockets were closed properly. Is there something different about how the system manages shutting down the shell processes with ShellMBS vs the xojo shell? I have to restart the entire machine before I can create another instance of them listening on a specific port and I definitely do not have to do that with the xojo shell. I’m not sure how to work around that. Of course the app shouldn’t crash ;) But thats not 100% possible to guarantee ;) The parent app is launched by launchd so it happily restarts where it left off when it happens, but using ShellMBS almost nothing works after it does so. Thanks, James James Sentman http://www.PlanetaryGear.org http://MacHomeAutomation.com _______________________________________________ mbsplugins@monkeybreadsoftware.info mailing list %(list_address)s https://ml-cgn08.ispgateway.de/mailman/listinfo/mbsplugins_monkeybreadsoftware.info
