/* oslib.c - functions present only in some unix versions. */

/* Copyright (C) 1995,2010 Free Software Foundation, Inc.

   This file is part of GNU Bash, the Bourne Again SHell.

   Bash is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   Bash is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "config.h"

#include "bashtypes.h"
#if defined (HAVE_SYS_PARAM_H)
#  include <sys/param.h>
#endif

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#if defined (HAVE_LIMITS_H)
#  include <limits.h>
#endif

#include "posixstat.h"
#include "filecntl.h"
#include "bashansi.h"

#if !defined (HAVE_KILLPG)
#  include <signal.h>
#endif

#include <stdio.h>
#include <errno.h>
#include "chartypes.h"

#include "shell.h"

#if !defined (errno)
extern int errno;
#endif /* !errno */

/*
 * Return the total number of available file descriptors.
 *
 * On some systems, like 4.2BSD and its descendants, there is a system call
 * that returns the size of the descriptor table: getdtablesize().  There are
 * lots of ways to emulate this on non-BSD systems.
 *
 * On System V.3, this can be obtained via a call to ulimit:
 *	return (ulimit(4, 0L));
 *
 * On other System V systems, NOFILE is defined in /usr/include/sys/param.h
 * (this is what we assume below), so we can simply use it:
 *	return (NOFILE);
 *
 * On POSIX systems, there are specific functions for retrieving various
 * configuration parameters:
 *	return (sysconf(_SC_OPEN_MAX));
 *
 */

#if !defined (HAVE_GETDTABLESIZE)
int
getdtablesize ()
{
#  if defined (_POSIX_VERSION) && defined (HAVE_SYSCONF) && defined (_SC_OPEN_MAX)
  return (sysconf(_SC_OPEN_MAX));	/* Posix systems use sysconf */
#  else /* ! (_POSIX_VERSION && HAVE_SYSCONF && _SC_OPEN_MAX) */
#    if defined (ULIMIT_MAXFDS)
  return (ulimit (4, 0L));	/* System V.3 systems use ulimit(4, 0L) */
#    else /* !ULIMIT_MAXFDS */
#      if defined (NOFILE)	/* Other systems use NOFILE */
  return (NOFILE);
#      else /* !NOFILE */
  return (20);			/* XXX - traditional value is 20 */
#      endif /* !NOFILE */
#    endif /* !ULIMIT_MAXFDS */
#  endif /* ! (_POSIX_VERSION && _SC_OPEN_MAX) */
}
#endif /* !HAVE_GETDTABLESIZE */

#if !defined (HAVE_MKFIFO) && defined (PROCESS_SUBSTITUTION)
int
mkfifo (path, mode)
     char *path;
     mode_t mode;
{
#if 0 && defined (S_IFIFO)  // [jart] cosmo local change
  return (mknod (path, (mode | S_IFIFO), 0));
#else /* !S_IFIFO */
  return (-1);
#endif /* !S_IFIFO */
}
#endif /* !HAVE_MKFIFO && PROCESS_SUBSTITUTION */

#define DEFAULT_MAXGROUPS 64

int
getmaxgroups ()
{
  static int maxgroups = -1;

  if (maxgroups > 0)
    return maxgroups;

#if defined (HAVE_SYSCONF) && defined (_SC_NGROUPS_MAX)
  maxgroups = sysconf (_SC_NGROUPS_MAX);
#else
#  if defined (NGROUPS_MAX)
  maxgroups = NGROUPS_MAX;
#  else /* !NGROUPS_MAX */
#    if defined (NGROUPS)
  maxgroups = NGROUPS;
#    else /* !NGROUPS */
  maxgroups = DEFAULT_MAXGROUPS;
#    endif /* !NGROUPS */
#  endif /* !NGROUPS_MAX */  
#endif /* !HAVE_SYSCONF || !SC_NGROUPS_MAX */

  if (maxgroups <= 0)
    maxgroups = DEFAULT_MAXGROUPS;

  return maxgroups;
}

long
getmaxchild ()
{
  static long maxchild = -1L;

  if (maxchild > 0)
    return maxchild;

#if defined (HAVE_SYSCONF) && defined (_SC_CHILD_MAX)
  maxchild = sysconf (_SC_CHILD_MAX);
#else
#  if defined (CHILD_MAX)
  maxchild = CHILD_MAX;
#  else
#    if defined (MAXUPRC)
  maxchild = MAXUPRC;
#    endif /* MAXUPRC */
#  endif /* CHILD_MAX */
#endif /* !HAVE_SYSCONF || !_SC_CHILD_MAX */

  return (maxchild);
}