The total number of file descriptors has a hard limit of 32767 per process,
but you're more likely to be constrained by the -F option to
procnto or the RLIMIT_NOFILE system resource.
The default value is 1000; the minimum is 100.
Note:
-
Sockets, named semaphores, and message queues all use file descriptors.
Connection IDs (coids) for side channels and server connection IDs (scoids)
are returned from a different space than file descriptors,
so they don't count towards the limit set by the procnto
-F option or RLIMIT_NOFILE.
- In the traditional implementation of message queues
(mqueue),
each call to
mq_open()
uses one file descriptor; in the alternate implementation
(mq),
each call to mq_open() uses two.
To determine the current limit, use the ksh builtin command,
ulimit,
(see the Utilities Reference), or call
getrlimit()
(see the QNX Neutrino C Library Reference).