getdtablesize - get file descriptor table size
#include <unistd.h>
int getdtablesize(void);
getdtablesize():
Since glibc 2.20:
_DEFAULT_SOURCE || ! (_POSIX_C_SOURCE >= 200112L)
Glibc 2.12 to 2.19:
_BSD_SOURCE || ! (_POSIX_C_SOURCE >= 200112L)
Before glibc 2.12:
_BSD_SOURCE || _XOPEN_SOURCE >= 500
getdtablesize() returns the maximum number of files a process can have
open, one more than the largest possible value for a file descriptor.
The current limit on the number of open files per process.
On Linux, getdtablesize() can return any of the errors described for
getrlimit(2); see NOTES below.
For an explanation of the terms used in this section, see attributes(7).
| Interface |
Attribute |
Value |
| getdtablesize () |
Thread safety |
MT-Safe |
SVr4, 4.4BSD (the getdtablesize() function first appeared in 4.2BSD). It
is not specified in POSIX.1; portable applications should employ
sysconf(_SC_OPEN_MAX) instead of this call.
The glibc version of getdtablesize() calls getrlimit(2) and
returns the current RLIMIT_NOFILE limit, or OPEN_MAX when that
fails.
This page is part of release 5.13 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the latest
version of this page, can be found at https://www.kernel.org/doc/man-pages/.