You have an existing block of text or code in vim. You want to re-format it to wrap to 80-characters.

:set textwidth=80

You might want this setting to apply automatically within certain file types like Markdown:

au BufRead,BufNewFile *.md setlocal textwidth=80

We have that setting in thoughtbot/dotfiles.

Select the lines of text you want to re-format:

v

Reformat it:

gq

Learn more:

:h gq

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