GETDTABLESIZE(2)                                    Linux Programmer's Manual                                   GETDTABLESIZE(2)



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
       This  page  is  part of release 3.25 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/.



Linux                                                      2007-07-26                                           GETDTABLESIZE(2)