Find fonts with Font Book. Right click and Show in Finder.
brew install fontforge
# Option 1: generate Powerline
git clone https://github.com/powerline/fontpatcher
cd fontpatcher/scripts/
# generate Menlo Regular for Powerline.otf
fontforge -script powerline-fontpatcher Menlo.ttc
# Option 2 (Recommended): generate Nerd Font
git clone https://github.com/ryanoasis/nerd-fonts
cd nerd-fonts/
# generate Menlo Regular Nerd Font Complete.otf
fontforge -script font-patcher --complete --progressbars --extension otf Menlo.ttc