sysdeps/mach/hurd/bits/local_lim.h

   1 /* Minimum guaranteed maximum values for system limits.  Hurd version.
   2    Copyright (C) 1993,94,96,98,2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* GNU has no arbitrary fixed limits on most of these things, so we
  21    don't define the macros.  Some things are unlimited.  Some are in
  22    fact limited but the limit is run-time dependent and fetched with
  23    `sysconf' or `pathconf'.  */
  24
  25 /* This one value is actually constrained by the `struct dirent'
  26    layout, in which the `d_namlen' member is only 8 bits wide.  */
  27
  28 #define NAME_MAX        255
  29
  30 /* POSIX.1 requires that we define NGROUPS_MAX (though none of the others
  31    is required).  GNU allows any number of supplementary groups,
  32    dynamically allocated.  So we pick a number which seems vaguely
  33    suitable, and `sysconf' will return a number at least as large.  */
  34
  35 #define NGROUPS_MAX     256
  36
  37 /* The maximum number of symbolic links that are allowed in a single file
  38    name resolution.  When a further link is encountered, the call returns
  39    ELOOP.  This name is a GNU extension; POSIX.1 has no such limit, and BSD
  40    calls it MAXSYMLINKS in <sys/param.h>.  (We define the name under
  41    _BSD_SOURCE even without _GNU_SOURCE because our <sys/param.h> uses it
  42    to define MAXSYMLINKS.)  */
  43
  44 #if defined __USE_GNU || defined __USE_BSD /* 1003.1a defines this */
  45 #define SYMLOOP_MAX     8
  46 #endif