我不小心删除了/etc/yum.repos.d目录中的所有文件
yum repolist all
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
repolist: 0
yum install svn
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
There are no enabled repos.
Run "yum repolist all" to see the repos you have.
To enable Red Hat Subscription Management repositories:
subscription-manager repos --enable <repo>
To enable custom repositories:
yum-config-manager --enable <repo>
如何还原特定目录的文件?