l.sh

function l {
  if [[ ! -t 0 ]]; then
    # stdin is not connected to a tty
    pager -
  elif [[ $# -eq 1 && -f "$1" ]]; then
    # single argument names a file
    pager "$1"
  else
    ls -CFL $*
  fi
}

pager.sh

function pager {
  case "$1" in
    *asc)
      gpg -dq "$1" | pager -
      clear
      ;;
    *bz|*bz2)
      LESSOPEN='|bzip2 -cdq -- %s' "$PAGER" "$1"
      ;;
    *gz)
      LESSOPEN='|gzip -cdq -- %s' "$PAGER" "$1"
      ;;
    *pdf|*png|*jpg)
      ql "$1"
      ;;
    *xz)
      LESSOPEN='|xz -cdq -- %s' "$PAGER" "$1"
      ;;
    *)
      "$PAGER" "$1"
      ;;
  esac
}