Re: remove last and first three lines from a file

From: Robert Katz (katz_at_hp.com)
Date: 12/28/04 

Date: Tue, 28 Dec 2004 19:44:34 GMT

John Savage wrote:
> "Prince" <gspk@yahoo.com> writes:
>
>>I forgot to mention, the dificulty I have is deleting the last three
>>lines. I can use sed '1,3d' to delete the first three.
>
>
> Any great need for efficiency? If not ....
>
> sed '1,3d;$d' datafile | sed '$d' | sed '$d'
>
> or, sed '1d;$d' datafile | sed '1d;$d' | sed '1d;$d'

In classical sed, not GNU, in which

"If no next line of input is available, the N command verb shall branch
  to the end of the script and quit without starting a new cycle or
copying the pattern space to standard output."

sed '
1,3d
4{N;N;}
N;P;D'

This is not as easily generalized as the awk routine. 

-- 
Regards,
---Robert

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