1、[root@localhost ~]# head -n 6 /opt/passwd | tail -n 1
2、[root@localhost ~]# find /etc/ -name "host*"
3、[root@localhost ~]# grep re /usr/share/rhel.xml > /root/files
4、tar -czf /back/etcback.tar.gz /etc
5、[root@localhost ~]# groupadd g1
[root@localhost ~]# chown redhat:g1 redhat.txt