ubuntu gcc 4.4.3 降級 gcc 4.3

1、安装gcc-4.3
$ sudo apt-get install gcc-4.3 g++-4.3
2、修gcc相关链接
$ cd /usr/bin
$sudo ln -snf gcc-4.3 gcc
$sudo ln -snf g++-4.3 g++
$sudo ln -snf cpp-4.3 cpp
3、如是64bit系统，则还需装如下包。
$ sudo apt-get install g++-multilib g++-4.3-multilib

ref: http://www.ways2u.com/?post=163

gcc 4.3 gcc 3.4 快速切換
使用 update-alternatives 工具
sudo update-alternatives --install /usr/bin/cpp cpp /usr/bin/cpp-3.4 30
sudo update-alternatives --install /usr/bin/cpp cpp /usr/bin/cpp-4.4 40

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-3.4 30
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.4 40

sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-3.4 30
sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.4 40

設定後 sudo update-alternatives --config gcc

Selection Path 優先級 Status
------------------------------------------------------------
0 /usr/bin/gcc-3.4 40 auto mode
* 1 /usr/bin/gcc-3.4 40 manual mode
2 /usr/bin/gcc-4.4 30 manual mode

Press enter to keep the current choice[*], or type selection number: 2
update-alternatives: using /usr/bin/gcc-4.4 to provide /usr/bin/gcc (gcc) in manual mode.
可看到版本切換摟

look: gcc -v
Thread model: posix
gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)