File Descriptors available

Hi everybody,

i need to know the total File Descriptors available in my system (total or
total for one process, anyone). I dont find this info in docs and anywhere
else in Internet.
We have a trouble in communication between process in QNX and process in SOLARIS and we think its related with the total of File Descriptors
available in QNX system. To confirm this, and to plan to change this conf.,
we need to know the max FDs available to one process (or the total available in the hole system) and the impacts in my system if i change this, and recompile the kernel.
if anyone knows it or knows where i find it… please, help me.



We had this trouble on QNX4.25 too, a lot of troubles with fds … i think we used the -H (or was it -N) option to Fsys back then
As a workaround we opened “random-temp-files” on the beginning and closed them again directly.

Sorry, i did not find a #define for MAX_FILES_PER_PROCESS :slight_smile:

Check the documentation of Proc32 and the -f option.

But Proc32 is just to kernel, right? I define FDs, using Proc32, in time to compile the QNX kernel. so, how i know the FDs defined, if i didn´t compiled the kernel?
Sorry if my doubts are stupid, but i´m new in QNX… :wink:

OK, i will find for this.


The QNX4 kernel cannot be compiled by end-users, it is a binary only. The kernel processes command line arguments (just like a regular process would) to control allocation of resources.

It has been a long time since I used QNX 4, but I think Mario is correct that the option is “-f”…

You don’t compile the kernel but install you build an image. The content of the image is usually found in /boot/build/hard.X edit this file to add the -f option. Then rebuild the image which you then copy as /.boot. The complete procedure is documented