centos7如何升级GCC编辑器、G++编译器， 安装多个版本及切换

001、系统

[root@localhost home]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)

002、当前gcc 及 g++版本

[root@localhost home]# gcc --version
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[root@localhost home]# g++ --version
g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

003、安装centos-release-scl

yum install centos-release-scl

004、安装devtoolset

yum install devtoolset-8-gcc*

005、激活对应的devtoolset版本

scl enable devtoolset-8 bash

006、查看版本

[root@localhost home]# gcc --version       ## 安装成功
gcc (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[root@localhost home]# g++ --version
g++ (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

注意以上只是临时安装成功，重启终端会自动切换为原来的版本。

007、安装其他gcc、g++版本

yum install devtoolset-11-gcc*

008、安装的所有gcc在/opt/rh/目录下：

[root@localhost home]# cd /opt/rh/
[root@localhost rh]# ls
devtoolset-11  devtoolset-8

009、不同版本的切换

[root@localhost rh]# gcc --version             ## 当前gcc版本
gcc (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[root@localhost rh]# source /opt/rh/devtoolset-11/enable   ## 切换至版本11
[root@localhost rh]# gcc --version                         ## 切换效果
gcc (GCC) 11.2.1 20220127 (Red Hat 11.2.1-9)
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

010、设定某一版本为系统启动的默认版本

mv /usr/bin/gcc /usr/bin/gcc-4.8.5
ln -s /opt/rh/devtoolset-8/root/bin/gcc /usr/bin/gcc
mv /usr/bin/g++ /usr/bin/g++-4.8.5
ln -s /opt/rh/devtoolset-8/root/bin/g++ /usr/bin/g++

011、测试设定效果

[root@localhost rh]# reboot         ## 重启
[root@localhost rh]# gcc --version    ## 开机自动启动为gcc 8版本
gcc (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[root@localhost rh]# g++ --version
g++ (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

参考：https://blog.csdn.net/baidu_39332177/article/details/122846140