Open a Terminal window.

Execute these shell commands (the $ indicates the prompt):

$ cd ~/Downloads
$ ls mongo*
$ tar xzf mongodb-osx-ssl-x86_64-3.4.7.tar
$ sudo mkdir –p /usr/local/mongodb
$ sudo mv mongodb-osx-x86_64-3.4.7 /usr/local/mongodb

These will decompress the file that you downloaded, create the folder /usr/local/mongodb, and then move the specified decompressed file to that folder. You may be asked for your computer password. The ls command will list the files that match the pattern mongo*.tar. Use that to get the right filename. (The one shown here was correct in August, 2017.)

Execute these commands next:

$ sudo mkdir -p /data/db
$ sudo chown johnrhubbard /data/db

Use your own username with the chown command. This creates the directory /data/db and gives you ownership of it.

Execute these commands next:

$ cd ~
$ touch .bash_profile
$ vim .bash_profile

This starts the vim editor, editing your .bash_profile file. All the commands that you save in that file will be executed automatically whenever you start a shell session.

In the vim editor, do this:

The first line defines the MONGO_PATH variable. Note that the first line is shown here on two lines. The second line adds that path to your PATH variable. The third line simply sets your PS1 prompt (this was discussed at the beginning of this chapter.) It's optional and you can set it to anything you want.

Execute this command next:

$ source .bash_profile

The source command executes the specified file. If you reset your PS1 prompt, you will see the result.

Finally, to check that Mongo is installed, execute this command:

$ mongo -version