sed question...

[Howard Goldstein]

Giorgos Keramidas wrote:
> On 2007-09-24 20:52, Gary Kline <kline at tao.thought.org> wrote:
>   
>> On Mon, Sep 24, 2007 at 11:07:20PM -0400, Howard Goldstein wrote:
>>     
>>>>  # 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 ?
>>>       
>
> If you _know_ that the file has 28 lines, yes.  If you don't,
> then itmay be tricky to 'guess' that -n 18 is the right option.
>
>   
In the bits you snipped he said he wanted to ditch everything after the
18th line. 

I didn't realize complexity was the goal.  Is this a homework assignment
Gary?