Centos7 gcc版本默认4.8.3，Red Hat 为了软件的稳定和版本支持，yum 上版本也是4.8.3，所以无法使用yum进行软件更新，所以使用scl。
scl软件集(Software Collections),是为了给 RHEL/CentOS 用户提供一种以方便、安全地安装和使用应用程序和运行时环境的多个（而且可能是更新的）版本的方式，同时避免把系统搞乱。
一、安装scl源
[root@localhost Bringing-Old-Photos-Back-to-Life]# yum install centos-release-scl scl-utils-build -y
二、查看scl有哪些源可以用
[root@localhost Bringing-Old-Photos-Back-to-Life]# yum list all --enablerepo='centos-sclo-rh'|grep gcc gcc.x86_64 4.8.5-44.el7 @base gcc-c++.x86_64 4.8.5-44.el7 @base libgcc.x86_64 4.8.5-44.el7 @base compat-gcc-44.x86_64 4.4.7-8.el7 base compat-gcc-44-c++.x86_64 4.4.7-8.el7 base compat-gcc-44-gfortran.x86_64 4.4.7-8.el7 base devtoolset-10-gcc.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-gcc-c++.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-gcc-gdb-plugin.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-gcc-gfortran.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-gcc-plugin-devel.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-libgccjit.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-libgccjit-devel.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-10-libgccjit-docs.x86_64 10.2.1-11.1.el7 centos-sclo-rh devtoolset-7-gcc.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-gcc-c++.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-gcc-gdb-plugin.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-gcc-gfortran.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-gcc-plugin-devel.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-libgccjit.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-libgccjit-devel.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-7-libgccjit-docs.x86_64 7.3.1-5.16.el7 centos-sclo-rh devtoolset-8-gcc.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-gcc-c++.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-gcc-gdb-plugin.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-gcc-gfortran.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-gcc-plugin-devel.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-libgccjit.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-libgccjit-devel.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-8-libgccjit-docs.x86_64 8.3.1-3.2.el7 centos-sclo-rh devtoolset-9-gcc.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-gcc-c++.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-gcc-gdb-plugin.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-gcc-gfortran.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-gcc-plugin-devel.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-libgccjit.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-libgccjit-devel.x86_64 9.3.1-2.2.el7 centos-sclo-rh devtoolset-9-libgccjit-docs.x86_64 9.3.1-2.2.el7 centos-sclo-rh gcc-gfortran.x86_64 4.8.5-44.el7 base gcc-gnat.x86_64 4.8.5-44.el7 base gcc-go.x86_64 4.8.5-44.el7 base gcc-objc.x86_64 4.8.5-44.el7 base gcc-objc++.x86_64 4.8.5-44.el7 base gcc-plugin-devel.x86_64 4.8.5-44.el7 base libgcc.i686 4.8.5-44.el7 base relaxngcc.noarch 1.12-6.el7 base relaxngcc-javadoc.noarch 1.12-6.el7 base [root@localhost Bringing-Old-Photos-Back-to-Life]#
安装7.3版本的gcc、gcc-c++、gdb
[root@localhost Bringing-Old-Photos-Back-to-Life]# yum install devtoolset-7-gcc.x86_64 devtoolset-7-gcc-c++.x86_64 devtoolset-7-gcc-gdb-plugin.x86_64 -y
查看scl安装的包列表
[root@localhost Bringing-Old-Photos-Back-to-Life]# scl --list
devtoolset-7
[root@localhost Bringing-Old-Photos-Back-to-Life]#
查看当前gcc版本
[root@localhost Bringing-Old-Photos-Back-to-Life]# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.8.5/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin --enable-initfini-array --disable-libgcj --with-isl=/builddir/build/BUILD/gcc-4.8.5-20150702/obj-x86_64-redhat-linux/isl-install --with-cloog=/builddir/build/BUILD/gcc-4.8.5-20150702/obj-x86_64-redhat-linux/cloog-install --enable-gnu-indirect-function --with-tune=generic --with-arch_32=x86-64 --build=x86_64-redhat-linux
Thread model: posix
gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC)
[root@localhost Bringing-Old-Photos-Back-to-Life]#
切换版本
[root@localhost Bringing-Old-Photos-Back-to-Life]# scl enable devtoolset-7 bash [root@localhost Bringing-Old-Photos-Back-to-Life]#
查看切换后的版本
[root@localhost Bringing-Old-Photos-Back-to-Life]# gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/opt/rh/devtoolset-7/root/usr/libexec/gcc/x86_64-redhat-linux/7/lto-wrapper Target: x86_64-redhat-linux Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,lto --prefix=/opt/rh/devtoolset-7/root/usr --mandir=/opt/rh/devtoolset-7/root/usr/share/man --infodir=/opt/rh/devtoolset-7/root/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --enable-plugin --with-linker-hash-style=gnu --enable-initfini-array --with-default-libstdcxx-abi=gcc4-compatible --with-isl=/builddir/build/BUILD/gcc-7.3.1-20180303/obj-x86_64-redhat-linux/isl-install --enable-libmpx --enable-gnu-indirect-function --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 7.3.1 20180303 (Red Hat 7.3.1-5) (GCC) [root@localhost Bringing-Old-Photos-Back-to-Life]#
目前是7.3.1了
使用exit命令退出scl环境
[root@localhost Bringing-Old-Photos-Back-to-Life]# exit
exit
再次查看版本
[root@localhost Bringing-Old-Photos-Back-to-Life]# exit exit [root@localhost Bringing-Old-Photos-Back-to-Life]# gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.8.5/lto-wrapper Target: x86_64-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin --enable-initfini-array --disable-libgcj --with-isl=/builddir/build/BUILD/gcc-4.8.5-20150702/obj-x86_64-redhat-linux/isl-install --with-cloog=/builddir/build/BUILD/gcc-4.8.5-20150702/obj-x86_64-redhat-linux/cloog-install --enable-gnu-indirect-function --with-tune=generic --with-arch_32=x86-64 --build=x86_64-redhat-linux Thread model: posix gcc version 4.8.5 20150623 (Red Hat 4.8.5-44) (GCC) [root@localhost Bringing-Old-Photos-Back-to-Life]#
变为原来的4.8.5了