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Gabs
Asked: 2015-08-01 05:35:26 +0800 CST

Change C++ version [duplicate]

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I am trying to change the C++ compiler version. I have both, 4.6.x AND 4.4 versions, I want to set it to the 4.4 version, so I am doing:

export "CXX=g++-4.4"

But when I run the command:

g++ -v

I am still getting this:

gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)

I am using Ubuntu 14.04.

I am using this tutorial:

https://stackoverflow.com/questions/7832892/how-to-change-the-default-gcc-compiler-in-ubuntu

14.04

1 Answers

  1. Best Answer

    The CXX variable doesn't affect how the shell resolves program name g++: that just follows the usual conventions of your executable search path $PATH, and is finally determined by a symbolic link e.g. on my 14.04 system

    $ which g++
/usr/bin/g++

    while 

    $ ls -l $(which g++)
lrwxrwxrwx 1 root root 7 Apr  7  2014 /usr/bin/g++ -> g++-4.8

    If you want to change that, you will need to re-make the symbolic link either manually e.g.

    sudo ln -sf g++-4.4 /usr/bin/g++

    or using the update-alternatives mechanism.

    However, many build processes will respect the setting of CXX (and the equivalent CC for the C compiler, FC for the Fortran compiler and so on) so that there is often no need to change the default compiler(s) via symlinks: if there is a particular software build that you are having difficulty with then I suggest you post a question about that specifically.

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