brew install sshpass
SoftwareInstalling sshpass from Homebrew? Be prepared for this:
$ brew install sshpass
==> Error: No available formula with the name "sshpass"
==> We won't add sshpass because it makes it too easy for
==> novice SSH users to ruin SSH's security.
The (security) needs of many outweigh the needs of the few. Normally I find such overbearing policy frustrating, but in this case: good call.