The number of file descriptors per process is determined by the operating system parameter open_max. The default value of open_max is 4096. For more information on setting open_max, see the HP Tru64 operating system documentation.
To obtain the current value of the open_max parameter, use the Korn or Bourne shell ulimit command:
ulimit -n
To obtain the number of current file descriptors programatically, use the sysconf or getdtablesize function.
