升级gcc
# 下载安装包
wget http://mirrors.aliyun.com/centos/7/os/x86_64/Packages/scl-utils-20130529-19.el7.x86_64.rpm
wget http://mirrors.aliyun.com/centos/7/os/x86_64/Packages/scl-utils-build-20130529-19.el7.x86_64.rpm
wget http://mirrors.aliyun.com/centos/7/sclo/x86_64/rh/Packages/d/devtoolset-9-binutils-2.32-16.el7.x86_64.rpm
wget http://mirrors.aliyun.com/centos/7/sclo/x86_64/rh/Packages/d/devtoolset-9-gcc-9.3.1-2.2.el7.x86_64.rpm
wget http://mirrors.aliyun.com/centos/7/sclo/x86_64/rh/Packages/d/devtoolset-9-gcc-c++-9.3.1-2.2.el7.x86_64.rpm
wget http://mirrors.aliyun.com/centos/7/sclo/x86_64/rh/Packages/d/devtoolset-9-libstdc++-devel-9.3.1-2.2.el7.x86_64.rpm
wget http://mirrors.aliyun.com/centos/7/sclo/x86_64/rh/Packages/d/devtoolset-9-runtime-9.1-0.el7.x86_64.rpm
# 打包(如果需要离线安装)
tar -czvf devtoolset9-vault.tar.gz
# 安装
rpm -Uvh scl-utils-20130529-19.el7.x86_64.rpm
rpm -Uvh devtoolset-9-*.rpm
# 设置
scl enable devtoolset-9 bash
# 验证
gcc --version