node & nodejs have different version

Steps that solved the same problem for me:

sudo apt-get remove nodejs
sudo ln -s /usr/bin/node /usr/bin/nodejs

Explanation

You have installed two versions of nodejs on your computer, so you need to remove one of them. Your situation:

node v5.0.0 - you will keep this one
nodejs v0.10.25 - this you can remove

You can remove nodejs package via apt-get remove command. This will also remove the file /usr/bin/nodejs and you will not get your error message again.

Now you can create a symbolic link called "/usr/bin/nodejs", that points on source "/usr/local/bin/node". In your example you have wrong order of paths "from" and "to"

sudo ln -s source_file myfile

More info about links creation: How symbolic links works

The error:

ln: failed to create symbolic link ‘/usr/bin/node’: File exists

is normally caused when you really have two versions of the Nodejs, a with the alias of the node and the other with the nodejs alias, as we can see on the result of the commands node --version and nodejs --version:

$ node --version
v5.0.0
$ nodejs --version
v0.10.25

so you can't create a symbolic link for a file that already exists.

To solve this you need to completely remove the two packages using:

sudo apt-get purge node
sudo apt-get purge nodejs
sudo rm -rf bin/node bin/node-waf include/node lib/node lib/pkgconfig/nodejs.pc share/man/man1/node

and reinstall only the nodejs package using the command:

sudo apt-get install nodejs

and create a symbolic link using:

ln -s /usr/bin/nodejs /usr/bin/node

or install the nodejs-legacy that will resolve this problem with the command:

sudo apt-get install nodejs-legacy