Date: Mon, 24 Sep 2007 23:07:20 -0400 From: Howard Goldstein <hg@queue.to> To: Gary Kline <kline@tao.thought.org> Cc: freebsd-questions@freebsd.org Subject: Re: sed question... Message-ID: <46F87B68.6090607@queue.to> In-Reply-To: <20070925013723.GA50027@thought.org> References: <20070925013723.GA50027@thought.org>
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Gary Kline wrote:
> My earlier post about deleting the first N lines was answered by
> this one-liner site {below}. I wasn't including any
> redirection; doing so finally resolved the problem. Now I need
> to delete every line from the 19th or so to the last line.
> Question one, can anybody explain the following syntax? What do
> "P", "D" "ba" represent, in other words?
>
>
> # delete the last 10 lines of a file
> sed -e :a -e '$d;N;2,10ba' -e 'P;D' # method 1
> sed -n -e :a -e '1,10!{P;N;D;};N;ba' # method 2
>
>
> Question two, can sed do its thing inline?
Wouldn't it be easier to use head -n 18 ?
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