coreutils/lib/physmem.c
2000-12-19 08:22:18 +00:00

59 lines
1.7 KiB
C

/* Calculate the size of physical memory.
Copyright 2000 Free Software Foundation, Inc.
This program 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 2, or (at your option)
any later version.
This program 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 this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Paul Eggert. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include "physmem.h"
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
/* Return the total amount of physical memory. */
double
physmem_total (void)
{
#if defined _SC_PHYS_PAGES && defined _SC_PAGESIZE
double pages = sysconf (_SC_PHYS_PAGES);
double pagesize = sysconf (_SC_PAGESIZE);
if (0 <= pages && 0 <= pagesize)
return pages * pagesize;
#endif
/* Guess 64 MB. It's probably an older host, so guess small. */
return 64 * 1024 * 1024;
}
/* Return the amount of physical memory available. */
double
physmem_available (void)
{
#if defined _SC_AVPHYS_PAGES && defined _SC_PAGESIZE
double pages = sysconf (_SC_AVPHYS_PAGES);
double pagesize = sysconf (_SC_PAGESIZE);
if (0 <= pages && 0 <= pagesize)
return pages * pagesize;
#endif
/* Guess 25% of physical memory. */
return physmem_total () / 4;
}