table of contents
GETDTABLESIZE(3) | Linux Programmer's Manual | GETDTABLESIZE(3) |
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():
- Since glibc 2.12:
-
_BSD_SOURCE ||
!(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) -
Before glibc 2.12: - _BSD_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
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¶
COLOPHON¶
This page is part of release 3.53 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/.
2013-02-05 | Linux |