How to insert text at beginning of a multi-line selection in vi/Vim

editingviemuvim

In Vim, how do I insert characters at the beginning of each line in a selection?

For instance, I want to comment out a block of code by prepending // at the beginning of each line assuming my language's comment system doesn't allow block commenting like /* */. How would I do this?

Best Answer

Press Esc to enter 'command mode'
Use Ctrl+V to enter visual block mode
Move Up/Downto select the columns of text in the lines you want to comment.
Then hit Shift+i and type the text you want to insert.
Then hit Esc, wait 1 second and the inserted text will appear on every line.

For further information and reading, check out "Inserting text in multiple lines" in the Vim Tips Wiki.

Use `\r` instead of `\n`.

Substituting by \n inserts a null character into the text. To get a newline, use \r. When searching for a newline, you’d still use \n, however. This asymmetry is due to the fact that \n and \r do slightly different things:

\n matches an end of line (newline), whereas \r matches a carriage return. On the other hand, in substitutions \n inserts a null character whereas \r inserts a newline (more precisely, it’s treated as the input CR). Here’s a small, non-interactive example to illustrate this, using the Vim command line feature (in other words, you can copy and paste the following into a terminal to run it). xxd shows a hexdump of the resulting file.

echo bar > test
(echo 'Before:'; xxd test) > output.txt
vim test '+s/b/\n/' '+s/a/\r/' +wq
(echo 'After:'; xxd test) >> output.txt
more output.txt

Before:
0000000: 6261 720a                                bar.
After:
0000000: 000a 720a                                ..r.

In other words, \n has inserted the byte 0x00 into the text; \r has inserted the byte 0x0a.

Best Answer

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Use \r instead of \n.

Related Topic

Use `\r` instead of `\n`.