If you don't give :colorscheme an argument then it shows the name of the colorscheme that vim is currently using. Is there a similar way in vim to show if an option is set or what the value of the option is set to if it isn't a boolean? For example, if I wanted to know whether autoindent is set or I wanted to know the value of textwidth, how would I find that?
Use the :set command.
:set autoindent? prints the option, and its value, if any. Vim toggle options (booleans, options that are on/off), like autoindent, are prefixed with no to indicate that they're turned off, so :set autoindent? will display autoindent or noautoindent.:set autoindent turns autoindent on.
:set textwidth will also print the value of the option. For number or string options, :set option is equivalent to :set option?.:set autoindent! inverts the option. autoindent becomes noautoindent.:set autoindent& reverts autoindent to its default value. :set option=value, e.g. set tabstop=3