Are you sure? [Y/n]. Why is the Y capitalized?

superbbrr · 05-20-2015, 01:08 PM

Here's another example:

Code:

read -r -p "Are you sure? [y/N] " response
case $response in
    [yY][eE][sS]|[yY]) 
        do_something
        ;;
    *)
        do_something_else
        ;;
esac

Why is the N capitalized here? Typing in n, N, or anything will result in *) being run. So [y/n] is the same thing as [y/N].

273 · 05-20-2015, 01:11 PM

It is capitalised because it is the default option -- in other words if you simply press <return> it will be selected. This is just the convention.

sgosnell · 05-21-2015, 03:50 PM

If you press any of the keys in YES, any case, then the yes option is used. Any other response cancels everything. Therefore N is the default, and the capital N presented to the user indicates that. As 273 said, that's the accepted convention, and has been for as long as I've been involved in computers, 30 years or so.