I'm writing a script which shows the git log for a directory when I cd into it. Such a log can be overwhelming, containing hundreds of lines. So far I have been limiting that to a hard-coded 20 lines (
... | head -n 20), which is fine on the screen at work, but too much on the smaller MacBook screen at home.
I would prefer the log to take up about half the (vertical) screen on either terminal. And "terminal" also changes: it's Gnome terminal at work, but iTerm2 at home. And I do not use screen or tmux.
How do I find the number of vertical lines available in a terminal from command line?