VI: How to add a prefix to every line? (such as # or //)

[no_mad]

Hi,

Any idea how to do this in VI or VIM.
Is it possible?

Thanks

 

[cdh7]

Hi,

Do a regular expression search and replace to replace the start of line (^) with the prefix. Like this:

:%s/^/\/\//g

or

:%s/^/#/g

Regards,
Chris

 

[amraldo]

What does the "%" in the command mean?
--
Amr Ali

 

[cdh7]

What does the "%" in the command mean?

That's the range over which you want to search. In this case, % means global so that all the lines in the file will be affected.

Regards,
Chris

 

[no_mad]

Hi Chris,

What if i want to insert # or // to specific number of line?
Means, from line no. 20 to line no. 30

Thanks.

 

[amraldo]

Then there is no need for the "g" flag I guess.
--
Amr Ali

 

[cdh7]

Then there is no need for the "g" flag I guess.

Oops, you're right. I always put in the "g" out of habit.

 

[amraldo]

Hi Chris,

What if i want to insert # or // to specific number of line?
Means, from line no. 20 to line no. 30

Thanks.

I guess it will be like this
:n,ms/^/#
or :n,ms/^\/\/\

where n is the number of the starting line while m is the number of the ending line
--
Amr Ali

 

[cdh7]

What if i want to insert # or // to specific number of line?
Means, from line no. 20 to line no. 30

Then you just change the range specifier. Something like this:
:20,30s/^/#/

If you're using VIM, you can also select the lines in visual mode by typing V and using the arrows to highlight some lines. Then, when you type : to start the search command, the range will automatically be inserted. Just continue typing s/^/#/ to complete the command.

Regards,
Chris

 

[amraldo]

I found this quick reference card for vi @ **broken link removed**
--
Amr Ali

 

[no_mad]

Yes, i got it.

Highlight the lines, then type this command
:'<,'>s/^/#/g

It works. Thanks for your help.