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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

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