[tpm] Fast(er) way of deleting X lines from start of a file

[G. Matthew Rice]

On Wed, 2009-09-30 at 11:39 -0400, Madison Kelly wrote: 
> Thus far, I've opened a file, read it in, shifted/ignored the first X 
> number of line and then wrote out the resulting file. This works, but 
> strikes me as horribly inefficient. Doubly so when the file could be 
> larger than RAM.
> 
>    So then, is there a more efficient/faster way of saying "Delete the 
> first X number of lines from file foo"?

Do you have to do it in Perl?  You could do:

    tail -n +N <in.txt >out.txt

where: N = X + 1

Regards, 
--matt