centos 7 升级g++ 到4.9

yum install centos-release-scl-rh centos-release-scl
yum check-update
yum install devtoolset-3-gcc  devtoolset-3-gcc-c++
source /opt/rh/devtoolset-3/enable

g++ -v 4.9.2 大功告成

2.安装 readline 

yum install readline-devel.x86_64 readline-devel.i386 ncurses-devel.i386 ncurses-devel.x86_64

ubuntu 14.04 LTS 升级g++ 到4.9 http://dreamyouxi.com:7129/blog/1363