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3 Ways to Comment Out Blocks of Code in vi

Liz Lam on September 19, 2019

Learning vi for the first time can be really intimidating. The learning curve is a bit high and there are many ways to do many things in this simp...

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Adrien Giboire • Oct 14 '19 • Edited

Quick tips:

To go to the beginning/end of your function/block, you can use %
Instead of typing the line numbers in your s command, you can highlight the lines and type :. It will prompt :'<,'> and you can continue with your command, i.e. s/^/\/\//, then Enter.

Hope I was clear :)

Liz Lam • Oct 16 '19

Thanks for the tip!

pianocomposer321 • Apr 25 '20

Quote:
What about //? Won't vi get confused since substitution uses / to separate the old value from the new value? This is where we need to use \ (forward slash) to escape the double back slashes that represent commenting.

Acutally, / is forward slash and \ is backslash. :)

Liz Lam • Apr 26 '20

Oh yes, you are right! Correcting now!

Ben Sinclair • Sep 19 '19

I use a plugin to do this because different languages have different requirements for comments and I'm lazy). I use commentary but there are a few that all do much the same thing.

Out of your options, I prefer #3, but I'd also consider using a macro and repeating it n times if the comments required changing the start and end of the line, like in CSS.

Using ctrl-smilieface to enter pedantic mode I feel the urge to point out that #3 is Vim only and not available in Vi.

Liz Lam • Sep 19 '19

I haven't had a lot of experiences with different plugins, but I will have to check out commentary.

So funny, yes. I tend to use the words 'vi' and 'vim' interchangeably and I was debating if I should make that distinction on this blog.

True story, I used vi proper for almost 10 years and for 8 of those years at work on an old RedHat Workstation distribution. A time came where all our work machines got upgraded to Ubuntu and I ended up with vim on my machine (I think it was vim-tiny). I wasn't familiar with visual mode. Everytime I accidentally hit CTRL + v, I would quickly ESC out because I didn't know what it was doing.

3 months ago, I decided to finally make the small effort to learn visual mode.

I love how you can learn new things all the time even in the tools you've been using forever!

Thanks for the comments!