一、思维导图二、练习#!/bin/bash mkdir ~/dir mkdir ~/dir/dir1 mkdir ~/dir/dir2 cp -r * ~/dir/dir1/ cp -r *.sh ~/dir/dir2/ cd ~/dir/dir2/ tar -cvJf dir2.tar.xz dir2 mv dir2.tar.xz ~/dir/dir1/ cd ~/dir/dir1 tar -xvJf dir2.tar.xz#!/bin/bash head -5 /etc/group|tail -1 mkdir /home/ubuntu/copy cd /home/ubuntu/copy sudo cp /etc/shadow test sudo chown root test sudo chmod 700 test#!/bin/bash strwww.hqyj.com expr substr $str 1 3 expr substr $str 5 4 expr substr $str 10 3#!/bin/bash read -p 请输入数组元素用空格分隔 arr echo 数组元素为${arr[]} echo 数组元素的个数为${#arr[]}
