This tutorial explains how you can install IFTop directly from source code on macOS. Tested on macOS 10.9.5.

Installing IFTop via official source code archive.

First grab a compressed archive from an official IFTop source site:

curl -O -L http://www.ex-parrot.com/pdw/iftop/download/iftop-0.17.tar.gz

Next, decompress the archive like this:

tar -xf iftop-0.*.tar.gz

Now go into the decompressed directory:

cd iftop-0.*

Run this configure command:

./configure

Once the configure process completes, run make:

make

Finally install it by running sudo make install:

sudo make install

And once it’s installed, run the command with -h to do a simple check to see it’s working:

iftop -h