CentOS7自带的GCC版本是4.8.5，如下所示：
# cat /etc/redhat-release CentOS Linux release 7.6.1810 (Core) # which gcc# gcc -vUsing built-in specs.COLLECT_GCC=gccCOLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.8.5/lto-wrapperTarget: x86_64-redhat-linuxConfigured 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-linuxThread model: posixgcc version 4.8.5 20150623 (Red Hat 4.8.5-36) (GCC)
在一些使用场景下需要高版本的GCC编译器，网上有介绍的下载源码编译，但个人在编译的时候老是会出一些问题，而且编译过程较为冗长，现简单copy 上的回答。
sudo yum install centos-release-sclsudo yum install devtoolset-7-gcc*scl enable devtoolset-7 bashwhich gccgcc --version
# scl enable devtoolset-7 bash # bash生效# which gcc/opt/rh/devtoolset-7/root/usr/bin/gcc# gcc -vUsing built-in specs.COLLECT_GCC=gccCOLLECT_LTO_WRAPPER=/opt/rh/devtoolset-7/root/usr/libexec/gcc/x86_64-redhat-linux/7/lto-wrapperTarget: x86_64-redhat-linuxConfigured 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-linuxThread model: posixgcc version 7.3.1 20180303 (Red Hat 7.3.1-5) (GCC)
升级成功！