假设当前目录为/home/cam Command New Working Directory cd book /home/cam/book cd book/wonderland /home/cam/book/wonderland cd ~/book/wonderland /home/cam/book/wonderland cd /usr/lib /usr/lib cd .. /home cd ../gryphon /home/gryphon cd ~gryphon /home/gryphon 假设我们从/usr/lib开始,输入不带参数的cd命令切换到用户主目录,输入命令cd -可回到/usr/lib目录