shell脚本实现仅保留某目录下最新的两个文件

#!/bin/sh

export DS_DIR=/home/cxy/test

if [ ! -d $DS_DIR ]; then
    mkdir $DS_DIR
else
    echo "$DS_DIR is not existed!"
fi

cd $DS_DIR
if [ $(ls -l | grep "install-*" | wc -l) > 3 ]; then
    echo "more than 2 dst_files in $DS_DIR"
    rm -r $(ls -rt | head -n2)
fi