誤刪tree命令如何恢復

誤刪tree命令如何恢復

考察rpm,yum的用法

一、刪除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...

二、直接yum或rpm安裝將提示tree已經安裝

[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、解決辦法：強制覆蓋安裝

[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、此時的tree已經可以使用

[root@centos7 ~]# tree . -d
.
├── Desktop
├── Documents
├── Downloads
├── Music
├── Pictures
├── Public
├── scripts
├── Templates
└── Videos

9 directories

五、yum的話可以重新安裝

[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。”