cd [目录名]切换当前目录至 [目录名]
命令：
cd / 说明：进入系统根目录,上面命令执行完后拿ls命令看一下linux命令，当前目录已经到系统根目录了
输出：
hc@hc-virtual-machine:~$ pwd
/home/hc
hc@hc-virtual-machine:~$ cd /
hc@hc-virtual-machine:/$ ls
bin dev initrd.img lib64 mnt root snap sys var
boot etc initrd.img.old lost+found opt run srv tmp vmlinuz
cdrom home lib media proc sbin swapfile usr
pwd的作用是查询当前所在目录
命令：
cd ..输出：
hc@hc-virtual-machine:~/PycharmProjects$ pwd
/home/hc/PycharmProjects
hc@hc-virtual-machine:~/PycharmProjects$ cd ..
hc@hc-virtual-machine:~$ pwd
/home/hc命令：
cd ../..输出：
hc@hc-virtual-machine:~/PycharmProjects$ pwd
/home/hc/PycharmProjects
hc@hc-virtual-machine:~/PycharmProjects$ cd ../..
hc@hc-virtual-machine:/home$ pwd
/home
“当前用户主目录”和“系统根目录”是两个不同的概念。进入当前用户主目录有两个方法。
命令1：
cd直接输入cd，然后回车
输出：
hc@hc-virtual-machine:~/PycharmProjects/my_test$ pwd
/home/hc/PycharmProjects/my_test
hc@hc-virtual-machine:~/PycharmProjects/my_test$ cd
hc@hc-virtual-machine:~$ pwd
/home/hc上面的命令是我在非root用户下操作的linux命令，现在我切换到root用户下再操作一遍
hc@hc-virtual-machine:~/PycharmProjects/my_test$ sudo su
root@hc-virtual-machine:/home/hc/PycharmProjects/my_test# pwd
/home/hc/PycharmProjects/my_test
root@hc-virtual-machine:/home/hc/PycharmProjects/my_test# cd
root@hc-virtual-machine:~# pwd
/root
命令2：
cd ~输出
hc@hc-virtual-machine:~/PycharmProjects/my_test$ pwd
/home/hc/PycharmProjects/my_test
hc@hc-virtual-machine:~/PycharmProjects/my_test$ cd ~
hc@hc-virtual-machine:~$ pwd
/home/hc命令
下一个教程：Linux 常用命令1
