#ifndef HAVE_GETPAGESIZE
# ifdef VMS
# define getpagesize() 512
# endif
# ifdef HAVE_UNISTD_H
# include <unistd.h>
# endif
# ifdef _SC_PAGESIZE
# define getpagesize() sysconf(_SC_PAGESIZE)
# else
# ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
# ifdef EXEC_PAGESIZE
# define getpagesize() EXEC_PAGESIZE
# else
# ifdef NBPG
# define getpagesize() NBPG * CLSIZE
# ifndef CLSIZE
# define CLSIZE 1
# endif
# else
# ifdef NBPC
# define getpagesize() NBPC
# else
# ifdef PAGESIZE
# define getpagesize() PAGESIZE
# endif
# endif
# endif
# endif
# else
# define getpagesize() 8192
# endif
# endif
#endif