android 7.1 找不到 ll (ls -l)命令

在使用android 5.1 时, 在adb shell 下, 可以使用ls 和 ll 命令, 但在7.1中, 发现 ll 命令无法使用:
/system/bin/sh: ll: not found

# Copyright (c) 2010, 2012, 2013, 2014
# Thorsten Glaser <tg@mirbsd.org>
# This file is provided under the same terms as mksh.
#-
# Minimal /system/etc/mkshrc for Android
#
# Support: https://launchpad.net/mksh
...
alias l='ls'
alias la='l -a'
alias ll='l -l'
alias lo='l -a -l'

# Copyright (c) 2010, 2012, 2013, 2014
# Thorsten Glaser <tg@mirbsd.org>
# This file is provided under the same terms as mksh.
#-
# Minimal /system/etc/mkshrc for Android
#
# Support: https://launchpad.net/mksh
: ${HOSTNAME:=$(getprop ro.product.device)}
: ${HOSTNAME:=android}
: ${TMPDIR:=/data/local/tmp}
export HOSTNAME TMPDIR
if (( USER_ID )); then PS1='$'; else PS1='#'; fi
PS4='[$EPOCHREALTIME] '; PS1='${|
  local e=$?
  (( e )) && REPLY+="$e|"
  return $e
}$HOSTNAME:${PWD:-?} '"$PS1 "
#add-start
alias l='ls'
alias la='l -a'
alias ll='l -l'
alias lo='l -a -l'
alias find='busybox find'
#add-end