In fact, after accidental deletion, Tab key to display the content or can be used
Many Linux commands are dependent libc.so.6 dynamic link library, if you accidentally deleted it, and basically all commands can not be used before many students solved by reinstalling the operating system, introduced today one kind of a way to solve the command:
[root@localhost ~]# LD_PRELOAD=/lib64/libc-2.12.so ln -s /lib64/libc-2.12.so /lib64/libc.so.6