GETDTABLESIZE
Section: Linux Programmer's Manual (2)
Updated: 2007-07-26
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NAME
getdtablesize - get descriptor table size
SYNOPSIS
#include <unistd.h>
int getdtablesize(void);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
getdtablesize():
_BSD_SOURCE || _XOPEN_SOURCE >= 500
DESCRIPTION
getdtablesize()
returns the maximum number of files a process can have open,
one more than the largest possible value for a file descriptor.
RETURN VALUE
The current limit on the number of open files per process.
ERRORS
On Linux,
getdtablesize()
can return any of the errors described for
getrlimit(2);
see NOTES below.
CONFORMING TO
SVr4, 4.4BSD (the
getdtablesize()
function first appeared in 4.2BSD).
It is not specified in POSIX.1-2001;
portable applications should employ
sysconf(_SC_OPEN_MAX)
instead of this call.
NOTES
getdtablesize()
is implemented as a libc library function.
The glibc version calls
getrlimit(2)
and returns the current
RLIMIT_NOFILE
limit, or
OPEN_MAX
when that fails.
The libc4 and libc5 versions return
OPEN_MAX
(set to 256 since Linux 0.98.4).
SEE ALSO
close(2),
dup(2),
getrlimit(2),
open(2)
COLOPHON
This page is part of release 3.22 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.