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			db_prefixtype='int'
		else
			db_prefixtype='size_t'
		fi
	else
		db_prefixtype='size_t'
		: XXX Maybe we should just give up here.
		$cat try.out >&4
		echo "Help:  I can't seem to compile the db test program." >&4
		echo "Something's wrong, but I'll assume you use $db_prefixtype." >&4
	fi
	$rm_try
	echo "Your version of Berkeley DB uses $db_prefixtype for prefix."
	;;
*)	db_prefixtype='size_t'
	;;
esac

: Include . in @INC
$cat <<EOM

Historically Perl has provided a final fallback of the current working
directory '.' when searching for a library. This, however, can lead to
problems when a Perl program which loads optional modules is called from
a shared directory. This can lead to executing unexpected code.

EOM

# When changing to exclude by default:
case "$default_inc_excludes_dot" in
    $undef|false|[nN]*) dflt="n" ;;
    *)                  dflt="y" ;;
esac
# To turn exclude off by default:
#case "$default_inc_excludes_dot" in
#    $define|true|[yY]*) dflt="y" ;;
#    *)                  dflt="n" ;;
#esac

rp='Exclude '.' from @INC by default? '
. ./myread
case "$ans" in
    [nN]|undef) default_inc_excludes_dot="$undef"  ;;
    *)          default_inc_excludes_dot="$define" ;;
esac

: Check what kind of inf/nan your system has
$echo "Checking the kind of infinities and nans you have..." >&4
$echo "(The following tests may crash.  That's okay.)" >&4
$cat >try.c <<EOP
#define DOUBLESIZE $doublesize
#$d_longdbl HAS_LONG_DOUBLE
#ifdef HAS_LONG_DOUBLE
#define LONG_DOUBLESIZE $longdblsize
#define LONG_DOUBLEKIND $longdblkind
#endif
#include <math.h>
#include <string.h>
#include <stdio.h>
/* Note that whether the sign bit is on or off
 * for NaN depends on the CPU/FPU, and possibly
 * can be affected by the build toolchain.
 *
 * For example for older MIPS and HP-PA 2.0 the quiet NaN is:
 * 0x7f, 0xf7, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 * 0x7f, 0xf4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 * (respectively) as opposed to the more usual
 * 0x7f, 0xf8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 *
 * Pre-IEEE-754 floating point format do not even have inf/nan support
 * at all.  They might have a "max" value (DBL_MAX), which may be deadly
 * to even mention, causing immediate SIGFPE or equivalent: this is
 * the case with VAX floating point, for example.
 */
static void bytes(void *v, unsigned int n) {
  unsigned char *p = (unsigned char *)v;
  int i;
  for (i = 0; i < n; i++) {
    printf("0x%02x%s", p[i], i < n - 1 ? ", " : "\n");
  }
}
int main(int argc, char *argv[]) {
   /* We cannot use 1.0/0.0 and 0.0/0.0 (with L suffixes for long double)
    * because some compilers are 'smart' and not only warn but refuse to
    * compile such 'illegal' values. */
   double dinf = exp(1e9);
   double dnan = sqrt(-1.0);
#ifdef HAS_LONG_DOUBLE
   long double ldinf = (long double)exp(1e9);
   long double ldnan = (long double)sqrt(-1.0);
# if LONG_DOUBLEKIND == 3 || LONG_DOUBLEKIND == 4
/* the 80-bit long doubles might have garbage in their excess bytes */
    memset((char *)&ldinf + 10, '\0', LONG_DOUBLESIZE - 10);
    memset((char *)&ldnan + 10, '\0', LONG_DOUBLESIZE - 10);
# endif
#endif
  if (argc == 2) {
    switch (argv[1][0]) {
    case '1': bytes(&dinf, sizeof(dinf)); break;
    case '2': bytes(&dnan, sizeof(dnan)); break;
#ifdef HAS_LONG_DOUBLE
    case '3': bytes(&ldinf, sizeof(ldinf)); break;
    case '4': bytes(&ldnan, sizeof(ldnan)); break;
#endif
    }
  }
  return 0;
}
EOP
set try
if eval $compile; then
    doubleinfbytes=`$run ./try 1`
    doublenanbytes=`$run ./try 2`
    case "$d_longdbl" in
    $define)
      longdblinfbytes=`$run ./try 3`
      longdblnanbytes=`$run ./try 4`
      ;;
    esac
else
    # Defaults in case the above test program failed.
    case "$doublekind" in
    1) # IEEE 754 32-bit LE
       doubleinfbytes='0x00, 0x00, 0xf0, 0x7f'