What's a quick way to comment/uncomment lines in Vim?


I have a Ruby code file open in vi, there are lines commented out with #:

class Search < ActiveRecord::Migration
  def self.up
    # create_table :searches do |t|
    #   t.integer :user_id
    #   t.string :name
    #   t.string :all_of
    #   t.string :any_of
    #   t.string :none_of
    #   t.string :exact_phrase
    #   t.timestamps
    # end

  def self.down
    # drop_table :searches

Say I want to uncomment all the lines in the first def ... end section. What's an efficient way to do that in Vim?

In general, I'm looking for an easy and fluid way to comment and uncomment lines. Here I'm dealing with Ruby code, but it could be JavaScript (//) or Haml (-#).

12/25/2013 2:00:50 AM

Accepted Answer

I use the NERD Commenter script. It lets you easily comment, uncomment or toggle comments in your code.

As mentioned in the comments:

for anyone who is confused by the usage, default leader is "\" so 10\cc will comment ten lines and 10\cu will uncomment those ten lines

6/29/2018 4:01:49 AM

To comment out blocks in vim:

  • press Esc (to leave editing or other mode)
  • hit ctrl+v (visual block mode)
  • use the / arrow keys to select lines you want (it won't highlight everything - it's OK!)
  • Shift+i (capital I)
  • insert the text you want, e.g. %
  • press EscEsc

To uncomment blocks in vim:

  • press Esc (to leave editing or other mode)
  • hit ctrl+v (visual block mode)
  • use the / arrow keys to select the lines to uncomment.

    If you want to select multiple characters, use one or combine these methods:

    • use the left/right arrow keys to select more text
    • to select chunks of text use shift + / arrow key
    • you can repeatedly push the delete keys below, like a regular delete button

  • press d or x to delete characters, repeatedly if necessary

Sometimes I'm shelled into a remote box where my plugins and .vimrc cannot help me, or sometimes NerdCommenter gets it wrong (eg JavaScript embedded inside HTML).

In these cases a low-tech alternative is the built-in norm command, which just runs any arbitrary vim commands at each line in your specified range. For example:

Commenting with #:

1. visually select the text rows (using V as usual)
2. :norm i#

This inserts "#" at the start of each line. Note that when you type : the range will be filled in, so it will really look like :'<,'>norm i#

Uncommenting #:

1. visually select the text as before (or type gv to re-select the previous selection)
2. :norm x

This deletes the first character of each line. If I had used a 2-char comment such as // then I'd simply do :norm xx to delete both chars.

If the comments are indented as in the OP's question, then you can anchor your deletion like this:

:norm ^x

which means "go to the first non-space character, then delete one character". Note that unlike block selection, this technique works even if the comments have uneven indentation!

Note: Since norm is literally just executing regular vim commands, you're not limited to comments, you could also do some complex editing to each line. If you need the escape character as part of your command sequence, type ctrl-v then hit the escape key (or even easier, just record a quick macro and then use norm to execute that macro on each line).

Note 2: You could of course also add a mapping if you find yourself using norm a lot. Eg putting the following line in ~/.vimrc lets you type ctrl-n instead of :norm after making your visual selection

vnoremap <C-n> :norm

Note 3: Bare-bones vim sometimes doesn't have the norm command compiled into it, so be sure to use the beefed up version, ie typically /usr/bin/vim, not /bin/vi

(Thanks to @Manbroski and @rakslice for improvements incorporated into this answer)


I have the following in my .vimrc:

" Commenting blocks of code.
augroup commenting_blocks_of_code
  autocmd FileType c,cpp,java,scala let b:comment_leader = '// '
  autocmd FileType sh,ruby,python   let b:comment_leader = '# '
  autocmd FileType conf,fstab       let b:comment_leader = '# '
  autocmd FileType tex              let b:comment_leader = '% '
  autocmd FileType mail             let b:comment_leader = '> '
  autocmd FileType vim              let b:comment_leader = '" '
augroup END
noremap <silent> ,cc :<C-B>silent <C-E>s/^/<C-R>=escape(b:comment_leader,'\/')<CR>/<CR>:nohlsearch<CR>
noremap <silent> ,cu :<C-B>silent <C-E>s/^\V<C-R>=escape(b:comment_leader,'\/')<CR>//e<CR>:nohlsearch<CR>

Now you can type ,cc to comment a line and ,cu to uncomment a line (works both in normal and visual mode).

(I stole it from some website many years ago so I can't completely explain how it works anymore :). There is a comment where it is explained.)


Specify which lines to comment in vim:

Reveal the line numbers:

:set number


:5,17s/^/#/     this will comment out line 5-17

or this:

:%s/^/#/        will comment out all lines in file

Here is how I do it:

  1. Go to first character on the first line you want to comment out.

  2. Hit Ctrl+q in GVIM or Ctrl+v in VIM, then go down to select first character on the lines to comment out.

  3. Then press c, and add the comment character.

Uncommenting works the same way, just type a space instead of the comment character.