"gcc --version" can't find gcc despite having g++-5 and gcc-5 installed?

Question

I want to have gcc-5 because I want c++14 support. So I removed the previous versions of gcc; gcc-4.8 and gcc-4.9 and installed gcc-5 and g++-5. But now when command gcc --version it replies:

The program 'gcc' is currently not installed. You can install it by typing:
sudo apt-get install gcc

On the other hand, if I command sudo apt-get install gcc-5, I get the reply gcc-5 is already the newest version. But if I command sudo apt-get install gcc it always tries to take gcc-4.8.

Why is this behaviour? How can I ensure I get gcc-5 when command sudo apt-get install gcc.

Thanks.

Answer 1

It is a bad to update libraries from a testing PPA, unless you know what you're doing.

You're not getting any response for gcc --version because you don't have the gcc program with version 5.x available in current apt-repositories. The package-manager (here apt) have maintained two different packages for the same program but different versions 4.x and 5.x.

You can't get gcc-5 when you type sudo apt-get install gcc because it will try to get package named gcc not gcc-5 from the list of repositories defined by apt. Instead I would suggest you to get gcc-5 and then replace it with gcc or replacing an alias in ~/.bashrc file.

If you want to replace your gcc-5 with gcc you can try this gist link. Or mainly

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install gcc-5 g++-5

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-5 60 --slave /usr/bin/g++ g++ /usr/bin/g++-5

A less recommended option would be to add

alias gcc='gcc-5

in you ~/.bashrc. It will use gcc-5 when you use it from terminal and any other calls to gcc won't trigger gcc-5.