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GETDTABLESIZE
Section: Linux Programmer's Manual (3)Updated: 2016-03-15
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NAME
getdtablesize - get file descriptor table sizeSYNOPSIS
#include <unistd.h>int getdtablesize(void);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
getdtablesize():
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- Since glibc 2.12:
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/* Glibc since 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE || ! (_POSIX_C_SOURCE >= 200112L) - Before glibc 2.12: _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.ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).| Interface | Attribute | Value |
| getdtablesize() | Thread safety | MT-Safe |
CONFORMING TO
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.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.SEE ALSO
close(2), dup(2), getrlimit(2), open(2)COLOPHON
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