dnl ------------------------------------------------------------------------
dnl Find a file (or one of more files in a list of dirs)
dnl ------------------------------------------------------------------------
dnl
AC_DEFUN(AC_FIND_FILE,
[
$3=NO
for i in $2;
do
  for j in $1;
  do
    if test -r "$i/$j"; then
      $3=$i
      break 2
    fi
  done
done
])