For HP-UX

The kernel parameters maxfiles and maxfiles_lim control the number of file descriptors available to any one process. The maximum number of files descriptors is 10,000 for 32-bit HP-UX systems and 60,000 for 64-bit HP-UX systems.

To display the current values for file descriptors, use the Korn or Bourne shell ulimit command:

ulimit -n