!    call openerq(lun,file,err)   !open readonly
!                int, char, logical
! If lun <= 0, then lunget will be called for it
! This is the same as opener except it doesn't print out and error message
! if the file doesn't exist, so can be used to check the existence of a file
subroutine openerq(ll,file,er)
  use cesr_utils
  implicit none
  integer ll,ierr
  character*(*) file
  character*256 filex
  logical er
  filex = ' '
  call fullfilename(trim(file),filex,er)
  if (ll <= 0) ll = lunget()
  open(unit=ll,file=trim(filex),action='read',status='old',iostat=ierr)
  er=ierr.ne.0
  return
end subroutine openerq