On OS X, be able to configure either Option or Command as Meta.

On OS X, be able to configure either Option or Command as Meta.

Personally I like using Command as the Esc-prefixing Meta key in
terminal sessions, because it occupies the same physical keyboard
position as the Alt key that I'm used to using on non-Macs. OS X
Terminal uses Option for that purpose (freeing up Command for the
conventional Mac keyboard shortcuts, of course), so I anticipate
differences of opinion.

Hence, here's a pair of OSX-specific config options which permit a
user to set either, or neither, or both of those modifier keys to
function as the terminal Meta key.