Updating brew package in bash script on OSX

Question

I'm working on a bash script that depends on specific package. This script will be used globally, on different machines. Some of them will have it, and some not.

How could I verify, as part of the bash script, if package is installed and to update/install it if needed?

My package manager (OSX 10.12) is brew.

Answer 1

You could write sth like:

#!/bin/bash

if brew ls --versions the_package_name > /dev/null; then
    # whatever you want to do
else
    brew install the_package_name
end