ok I understand now.
On Thu, Feb 16, 2012 at 3:17 PM, Raul Miller <rauldmil...@gmail.com> wrote: > You could make that into a shared object and load it in J using cd, > but if the OS requires hidden files to be open in every process, that > could also be a source of problems. I also do not have access to a > mac, so I can't tell you what you would need to do there, to run it > from under cd. > > Typically, though, a unix OS has three open file descriptors in a > process, and closing them prevents their use but has no other > consequences: > > 0: standard input > 1: standard output > 2: standard error > > Closing standard input means you cannot receive any further input > > Closing standard output means that console messages cease (or that > whatever you are writing to -- another file, or whatever) fails. > > Closing standard error does the same thing for error notifications. > > Closing these files can cause problems for your code (which is why the > usual approach is to reopen these files using /dev/null as the > underlying file), but should not hurt the OS. > > -- > Raul > > On Thu, Feb 16, 2012 at 9:55 AM, Ian Clark <earthspo...@gmail.com> wrote: >> Thanks, Raul. >> >> I can't see how to use your C routine without compiling it and calling >> it using 2!:1 (is that what you meant me to do?) It might seriously >> corrupt MacOS, which has lots of hidden files open, so I daren't try >> it. Anyway, can it be an open child file, if the problem doesn't arise >> with jconsole (jcon701) used in place of JHS? >> >> Now I've at last got my browse tool >> http://www.jsoftware.com/jwiki/IanClark/LoBrow working with JHS (by >> launching an essential "client" process independently, so as to get >> round the 2!:1 hang-up) a lot is coming clear. I think Bill has the >> right idea. JHS uses smoutput in an essential way to execute input >> sentences, and it can't just be turned off by setting smoutput_z_=: >> empty. This impacts on the timer to be used with JHS too, see recent >> thread. >> >> On Thu, Feb 16, 2012 at 1:51 PM, Raul Miller <rauldmil...@gmail.com> wrote: >>> I do not know, either, but you can close an already closed file handle, so: >>> >>> #include <unistd.h> >>> >>> void closeMostFiles() { >>> int f; >>> for (f= 0; f < 256; f++) { >>> close(f); >>> } >>> } >>> >>> If using that routine remedies the symptom you are seeing, it will be >>> worth looking at this in more depth. If not, it will probably be a >>> different issues. >>> >>> -- >>> Raul >>> >>> On Tue, Feb 14, 2012 at 6:27 PM, Ian Clark <earthspo...@gmail.com> wrote: >>>> I wasn't aware any file handles were inherited. Where do I find them >>>> to close? (...Unix rabbit). >>>> >>>> (The same code works without trouble in j602.) >>>> >>>> On Tue, Feb 14, 2012 at 9:25 PM, Raul Miller <rauldmil...@gmail.com> wrote: >>>>> Have you tried closing the file handles the child process inherits >>>>> from the parent? >>>>> >>>>> -- >>>>> Raul >>>>> >>>>> On Tue, Feb 14, 2012 at 4:04 PM, Ian Clark <earthspo...@gmail.com> wrote: >>>>>> 2!:1 is not truly asynchronous in JHS, it seems. The net result is >>>>>> that I cannot see how to launch a child process without the session >>>>>> hanging until the child terminates. >>>>>> >>>>>> Strange to say, the jijx session immediately resumes, and will accept >>>>>> (re-)input. But it will not execute the inputted expression. Inside a >>>>>> verb however, execution continues past 2!:1 (which successfully forks >>>>>> the child process), but after completion of the verb the session is >>>>>> silent (until the child process is terminated). >>>>>> >>>>>> Example: >>>>>> Suppose test6s.wav is a sound file lasting 6 seconds. (Chosen to last >>>>>> long enough to allow "i.6" to be entered.) >>>>>> >>>>>> 2!:1 'afplay ~/wav/test6s.wav &' >>>>>> i.6 >>>>>> 0 1 2 3 4 5 >>>>>> >>>>>> The jijx accepts i.6 but hangs until test6s.wav finishes playing. Only >>>>>> then does 0 1 2 3 4 5 appear. >>>>>> >>>>>> JVERSION >>>>>> Engine: j701/2011-01-10/11:25 build: Feb 6 2011 16:16:29 >>>>>> Library: 7.01.055 >>>>>> Platform: Darwin 64 >>>>>> Installer: j701a_mac64.dmg >>>>>> ---------------------------------------------------------------------- >>>>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>>> ---------------------------------------------------------------------- >>>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
