File descriptors

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.

Sockets, named semaphores, message queues, and connection IDs (coids) all use file descriptors.

To determine the current limit, use the ksh builtin command, ulimit , (see the Utilities Reference), or call getrlimit() (see the C Library Reference).