ubuntu GCC 版本切换

(1)  查看gcc以及g++的版本

gcc  -v

g++ -v

star@ai:~
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.5.0-12ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.5.0 20171010 (Ubuntu 5.5.0-12ubuntu1)
star@ai:~
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.5.0-12ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 5.5.0 20171010 (Ubuntu 5.5.0-12ubuntu1)
star@ai:~
$

当前的版本是5.5

(2) 现在需要切换到6.0

首先安装gcc6.0

sudo apt-get install gcc-6.0
sudo apt-get install g++-6.0

(3) 进入/usr/bin 目录

ll 查看

lrwxrwxrwx  1 root root           14 10月 12 13:29  g++ -> /usr/bin/g++-5*
-rwxr-xr-x  1 root root        13288 4月  23  2016  g3topbm*
-rwxr-xr-x  1 root root       911744 4月  12  2018  g++-5*
lrwxrwxrwx  1 root root           22 4月  24 13:16  g++-6 -> x86_64-linux-gnu-g++-6*
lrwxrwxrwx  1 root root           22 7月  26 20:25  g++-7 -> x86_64-linux-gnu-g++-7*
-rwxr-xr-x  1 root root        10232 2月   4  2018  gamma4scanimage*
-rwxr-xr-x  1 root root        18504 9月  17 20:52  gapplication*
-rwxr-xr-x  1 root root       277248 6月  22 17:27  gatttool*
-rwxr-xr-x  1 root root        14376 3月  24  2018  gc*
-rwxr-xr-x  1 root root       235600 4月  11  2018  gcalccmd*
lrwxrwxrwx  1 root root           21 10月 12 10:18  gcc -> /etc/alternatives/gcc*
-rwxr-xr-x  1 root root       907648 4月  12  2018  gcc-5*
lrwxrwxrwx  1 root root           22 4月  24 13:16  gcc-6 -> x86_64-linux-gnu-gcc-6*
lrwxrwxrwx  1 root root           22 7月  26 20:25  gcc-7 -> x86_64-linux-gnu-gcc-7*
lrwxrwxrwx  1 root root            8 4月   7  2018  gcc-ar -> gcc-ar-7*

可以发现g++ 链接到g++-5*

(4) gcc版本切换

sudo rm gcc
sudo ln -s /usr/bin/gcc-6* gcc
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6 10

sudo rm g++
sudo ln -s /usr/bin/g++-6* g++

(5)  查看是否切换成功

lrwxrwxrwx  1 root root           14 8月  23 11:03  g++ -> /usr/bin/g++-6*
-rwxr-xr-x  1 root root        13288 4月  23  2016  g3topbm*
lrwxrwxrwx  1 root root           22 4月  24 13:16  g++-6 -> x86_64-linux-gnu-g++-6*
lrwxrwxrwx  1 root root           22 4月  15 12:52  g++-7 -> x86_64-linux-gnu-g++-7*
-rwxr-xr-x  1 root root        10232 2月   4  2018  gamma4scanimage*
-rwxr-xr-x  1 root root        18504 9月  17 20:52  gapplication*
-rwxr-xr-x  1 root root       277248 6月  22 17:27  gatttool*
-rwxr-xr-x  1 root root        14376 3月  24  2018  gc*
-rwxr-xr-x  1 root root       235600 4月  11  2018  gcalccmd*
lrwxrwxrwx  1 root root           14 8月  23 11:03  gcc -> /usr/bin/gcc-6*
-rwxr-xr-x  1 root root       907648 4月  12 04:17  gcc-5*
lrwxrwxrwx  1 root root           22 4月  24 13:16  gcc-6 -> x86_64-linux-gnu-gcc-6*
lrwxrwxrwx  1 root root           22 4月  15 12:52  gcc-7 -> x86_64-linux-gnu-gcc-7*

g++ -v

gcc -v

ln -s的用法

ln -s  原始文件  快捷方式(目标文件)