Re: Delete only the nth block of text, multi-line

On Thu, 26 Feb 2015 12:12:24 +0200, "Lars Noodén [email protected]
[sed-users]" <[email protected]> wrote:

> Using GNU sed 4.2.2-4ubuntu1 on Ubuntu 14.04 LTS GNU/Linux
> 
> 
> I have some blocks of text spread over multiple lines and delimited by [
> and ].  ( See the tail of the message for an example. )  I'd like to
> delete the nth [ ] block.  The following pattern will delete all [ ]
> blocks:
> 
> 
>  sed '/^\[$/,/^\]/d' in > out
> 
> 
> That deletes more than I want deleted.  How can I make a sed formula or
> two that only deletes the nth block and leaves the others?
> 
> 
> Regards,
> /Lars
> 
> 
> ###
> 
> 
> foo
> [
>   aaa
>   bbb
>   ccc
> ]
> [
>   ccc
>   bbb
>   aaa
> ]
> [
>   bbb
>   ccc
>   aaa
> ]
> [
>   bbb
>   aaa
>   ccc
> ]
> bar

With some assumptions (the main one being that a block does not contain a
lone ]), you can slurp the whole file and use the normal s///n syntax:

:loop
$!{
  N
  b loop
}
s/\[[^]]*\]//3

change the 3 on the last line to the value you want. As with almost any
solution, that may or may not be appropriate for your actual data and use
case.


-- 
D.