How to remove the new line in redir command?

Question

I am using a command like this:

:redir @+ | set guifont | redir END

The output of the command above is:

  guifont=Source Code Pro:h14

Note the blank line at the beginning. How can I remove it? I tried the following:

:redir @+ | set guifont | redir END | %s/^\n//

But it doesn't work.

Answer 1

You were on the right track trying to substitute the newline with nil, but :%s works on a buffer. What you needed to execute the substitution on is the content of the clipboard, which resides in the clipboard register (see :h @r).

The correct way to capture the clean output of a command then is this:

redir @+ | set guifont | redir END | let @+ = substitute(@+, '\n', '', '')

But this was the correct way of your approach. There are other, better ways. For example, instead of using the convoluted way of :h redir, we can directly capture the output of a command with :h execute() and put it in the clipboard register. Any leading and trailing newline and whitespace can be removed with :h trim().

let @+ = trim(execute('set guifont'))

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This answer deals with capturing the output of an ex-command, not taking into account what the command is. For the exact use case of this question, which is to capture the output of a set-option command, it's simpler to use Christian Brabandt's answer

Answer 2

For getting the value of options, vim provides a better way, see :h expr-option

So to get the option value of the 'guifont' setting, you can simply use:

:echo &guifont

You can put the value in the system clipboard with:

:let @+ = &guifont