Shell 字符串处理

练习

需求描述：
变量string="Bigdata process framework is Hadoop, Hadoop is an open source project"
执行脚本后， 打印输出string 字符串变量，并给出用户以下选项：
1、打印string长度
2、删除字符串中所有的Hadoop
3、替换第一个Hadoop为Mapreduce
4、替换全部Hadoop为Mapreduce
用户输入数字1|2|3|4，可以执行对应的功能，输入q|Q则退出交互模式

变量处理语法说明

image.png

完整代码

string="Bigdata process framework is Hadoop, Hadoop is an open source project"

function print_tips
{
    echo "**********************"
    echo "1、打印string长度"
    echo "2、删除字符串中所有的Hadoop"
    echo "3、替换第一个Hadoop为Mapreduce"
    echo "4、替换全部Hadoop为Mapreduce"
    echo "**********************"
}

function len_of_string
{
    echo ${#string}
}

function del_hadoop
{
    echo ${string//Hadoop/} 
}

function rep_hadoop_mapreduce_first
{
    echo ${string/Hadoop/Mapreduce}
}

function rep_hadoop_mapreduce_all
{
    echo ${string//Hadoop/Mapreduce}
}

while true
do
    echo "【 string=$string 】"
    echo
    print_tips
    read -p "Please input 1|2|3|4|q|Q: " choice
    
    case $choice in
    1)
    len_of_string;;
    2)
    del_hadoop;;
    3)
    rep_hadoop_mapreduce_first;;
    4)
    rep_hadoop_mapreduce_all;;
    q|Q)
    exit;;
    *)
    echo "Error, input only in {1|2|3|4|q|Q}";;
    esac
    
done

运行效果

image.png