1GETDTABLESIZE(2) Linux Programmer's Manual GETDTABLESIZE(2)
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6 getdtablesize - get descriptor table size
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9 #include <unistd.h>
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11 int getdtablesize(void);
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13 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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15 getdtablesize(): _BSD_SOURCE || _XOPEN_SOURCE >= 500
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18 getdtablesize() returns the maximum number of files a process can have
19 open, one more than the largest possible value for a file descriptor.
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22 The current limit on the number of open files per process.
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25 On Linux, getdtablesize() can return any of the errors described for
26 getrlimit(2); see NOTES below.
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29 SVr4, 4.4BSD (the getdtablesize() function first appeared in 4.2BSD).
30 It is not specified in POSIX.1-2001; portable applications should
31 employ sysconf(_SC_OPEN_MAX) instead of this call.
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34 getdtablesize() is implemented as a libc library function. The glibc
35 version calls getrlimit(2) and returns the current RLIMIT_NOFILE limit,
36 or OPEN_MAX when that fails. The libc4 and libc5 versions return
37 OPEN_MAX (set to 256 since Linux 0.98.4).
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40 close(2), dup(2), getrlimit(2), open(2)
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43 This page is part of release 3.25 of the Linux man-pages project. A
44 description of the project, and information about reporting bugs, can
45 be found at http://www.kernel.org/doc/man-pages/.
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49Linux 2007-07-26 GETDTABLESIZE(2)