shell编程基础之根据输入进行相应的操作

这个题目是

输入A：创建自己名字的文件夹，如果有这个文件夹的话，就读取file1和file2的文件内容

输入B：获取当前用户对file1和file2文件权限

输入C：内容转为大写

输入D：计算连接和文件数目

输入E：计算文件空行数目

以下是我的代码:

#! bin/bash
read opts;
case $opts in
'A') 
    if [ -d ~/li ];then
        cp ./file1 ~/li;
        cp ./file2 ~/li;
        cat ~/li/file1;
        cat ~/li/file2;    
    else
        mkdir ~/li;
        chmod -R 755 ~/li;
    fi
    ;;    
'B')    if [ -d ~/liwei ];then
        file1=$(ls -l ~/li | grep 'file1'| awk -F " " '{print $1}' | cut -d '.' -f 1);
        file2=$(ls -l ~/li | grep 'file2'| awk -F " " '{print $1}' | cut -d '.' -f 1);
        echo your power of file1 is $file1;
        echo your power of file2 is $file2;
    else
        echo please excute 'A' first;
    fi
    ;;    
'C')    if [ -d ~/li];then
        file1=$(cat ~/li/file1);
        file2=$(cat ~/li/file2);
    
        upper=$(echo $file1 | tr '[a-z]' '[A-Z]');
        lower=$(echo $file2 | tr '[a-z]' '[A-Z]');
        
        echo 'uppercase show of  file1 and file2:';
        echo $upper;
        echo $lower;
    else
        echo please excute 'A' first;
    fi    
    ;;
'D')    file_str=$(ls -l  /dev | awk -F " " '{print $1}' | cut -c 1 | tr 
 , );
    file_arr=($file_str);
    l_num=0;
    d_num=0;
    for x in ${file_arr[@]}
    do 
        if [ "$x" = "d"  ];then
            d_num=$(($d_num + 1));
        fi
        if [ "$x" = "l" ];then
            l_num=$(($l_num + 1));
        fi
    done
    echo the number of directory in dev is $d_num;
    echo the number of link in dev is $l_num;
    ;;
'E')    line_num=0;
    test_num=0;
    if [ -d ~/li ];then
        
        while read line
        do
            if [[ ! -n $line  ]];then
                line_num=$(($line_num + 1));
            fi
        done < ~/li/file1
        echo "the number of blank line is $line_num"; 
    else
        echo please excute 'A' first.
    fi
    ;;
esac
exit