1. 修改鏡像源
使用的鏡像源爲清華大學開源軟件鏡像站，修改鏡像源參考鏈接爲：https://mirror.tuna.tsinghua.edu.cn/help/centos/
1.1 備份並修改原有文件
備份代碼爲：
cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
然後編輯 /etc/yum.repos.d/CentOS-Base.repo 文件，在 mirrorlist= 開頭行前面加 # 註釋掉；並將 baseurl= 開頭行取消註釋（如果被註釋的話），把該行內的域名（例如mirror.centos.org）替換爲 mirrors.tuna.tsinghua.edu.cn。
1.2 備份並替換原有文件
備份代碼爲：
cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
替換後的文件內容如下所示，需要注意的是最好把換行符\r\n修改爲\n：
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-7
#released updates
[updates]
name=CentOS-$releasever - Updates
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-7
2. 安裝基本庫
yum install gcc
yum install gcc-g++
yum install gdb