How to use the matched text in the replacement text in Vim

Question

I have a block of codes with timestamp in front of each line like this:

12/02/2010 12:20:12 function myFun()
12/02/2010 12:20:13 {....

The first column is a date time value. I would like to comment them out by using Vim, thus:

/*12/02/2010 12:20:12*/ function myFun()
/*12/02/2010 12:20:13*/ {....

I tried to search for date first:

/\d\d\/\d\d\/\d\d\d\d \d\d:\d\d:\d\d

I got all the timestamps marked correctly. However When I tried to replace them by the command:

%s/\d\d\/\d\d\/\d\d\d\d \d\d:\d\d:\d\d/\/*\d\d\/\d\d\/\d\d\d\d \d\d:\d\d:\d\d*\// 

I got the following result:

/*dd/dd/dddd dd:dd:dd*/ function myFun()
/*dd/dd/dddd dd:dd:dd*/ {....

I think I need to name the search part and put them back in the replace part. How I can do it?

Answer 1

I would actually not us a regex to do this. It takes too long to enter the correct formatting. I would instead use a Visual Block. The sequence works out to be something like this.

<C-V>}I/* <ESC>
3f\s
<C-V>I */

I love regex, and don't want to knock the regex solutions, but find when doing things with pre-formatted blocks, that this is easier, and requires less of a diversion from the real task, which isn't figuring out how to write a regex.

Answer 2

:%s/^\([0-9/]* [0-9:]* \)\(.*\)/\/*\1*\/ \2/

Answer 3

I suppose I would just do something like:

:%s-^../../.... ..:..:..-/* & */-

Answer 4

%s/\d\d\/\d\d\/\d\d\d\d \d\d:\d\d:\d\d/\/*&*\//