1.echo

cat >> a.txt <<-EOF

[192.168.124.106](192.168.124.106) controller

[192.168.124.107](192.168.124.107) compute

[192.168.124.108](192.168.124.108) cinder

EOF

2.centos换阿里源

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

3.shell

• 递增字符串

for i in `seq 100 150`;do echo abc-$i; done

4.查看当前文件夹大小

[root@qa1v29]:/opt# du -sh *
39M ZenTaoPMS.10.3.stable.zbox_64.tar.gz
65M cni
279M    zbox