NAME
getdtablesize() — get the size of the per-process file descriptor table
SYNOPSIS
#include <unistd.h>
int getdtablesize(void);
DESCRIPTION
The
getdtablesize()
function returns the maximum number of file descriptors that can
currently be stored in a process' file descriptor table.
This maximum number is also known as the soft limit for open files, and
can be adjusted up to the hard limit by calling
setrlimit().
The entries in the descriptor table are numbered with small integers
starting at 0 (zero).
The
getdtablesize()
function returns the total number of file descriptors that a process can
have open simultaneously.
Each process is limited to a current maximum (soft limit) and a fixed
upper bound (hard limit) of open file descriptors.
This limit is at least 32.
The system-defined limits are configurable.
See the descriptions of the
maxfiles_lim
and
maxfiles
kernel parameters in
maxfiles_lim(5)
and
maxfiles(5),
respectively, for information about changing the system-defined,
per-process limit on open file descriptors.
STANDARDS CONFORMANCE
getdtablesize():
XSH4.2, XSH5.0
RETURN VALUES
The
getdtablesize()
function returns the size of the descriptor table (soft limit), and is
always successful.
