trusty (3) getdtablesize.3.gz

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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():
           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
       close(2), dup(2), getrlimit(2), open(2)


COLOPHON
       This  page  is  part  of  release 3.54 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/.