误删tree命令如何恢复
考察rpm,yum的用法
一、删除tree命令，tree命令不可用
[root@CentOS7 ~]# which tree
/usr/bin/tree
[root@centos7 ~]# rm -f /usr/bin/tree
[root@centos7 ~]# tree .
bash: tree: command not found…
[root@centos7 ~]# yum install tree
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirror.bit.edu.cn
* extras: mirrors.tuna.tsinghua.edu.cn
* updates: mirrors.tuna.tsinghua.edu.cn
base | 3.6 kB 00:00:00
extras | 3.4 kB 00:00:00
nginx | 2.9 kB 00:00:00
updates | 3.4 kB 00:00:00
Package tree-1.6.0-10.el7.x86_64 already installed and latest version
Nothing to do
[root@centos7 ~]# rpm -ivh /misc/cd/Packages/tree-1.6.0-10.el7.x86_64.rpm
Preparing… ################################# [100%]
package tree-1.6.0-10.el7.x86_64 is already installed
三、解决办法：强制覆盖安装
[root@centos7 ~]# rpm –help
–replacepkgs reinstall if the package is already present
[root@centos7 ~]# rpm -ivh /misc/cd/Packages/tree-1.6.0-10.el7.x86_64.rpm –replacepkgs
Preparing… ################################# [100%]
Updating / installing…
1:tree-1.6.0-10.el7 ################################# [100%]
四、此时的tree已经可以使用
[root@centos7 ~]# tree . -d
.
├── Desktop
├── Documents
├── Downloads
├── Music
├── Pictures
├── Public
├── scripts
├── Templates
└── Videos
9 directories
五、yum的话可以重新安装
[root@centos7 ~]# yum –help
reinstall reinstall a package
[root@centos7 ~]# rm -f /usr/bin/tree
[root@centos7 ~]# tree -d .
-bash: /usr/bin/tree: No such file or directory
[root@centos7 ~]# yum reinstall tree -y
[root@centos7 ~]# tree -d .
.
├── Desktop
├── Documents
├── Downloads
├── Music
├── Pictures
├── Public
├── scripts
├── Templates
└── Videos
9 directories。”
