Re: [RndTbl] Easy script question?

Sometimes, it's the simple solutions that elude us... :)

But wait! Compatibility alert! Using a negative line count on head(1) is a GNU extension, and likely won't work with more "traditional" UNIX implementations.

Gilbert

On 04/03/2015 4:10 PM, John Lange wrote:

man head

head --lines=-5 textfile.txt

all but the last 5 lines.

On Wed, Mar 4, 2015 at 3:49 PM, Robert Keizer <robert@keizer.ca mailto:robert@keizer.ca> wrote:

Idea from thread below:

| awk '{if(a) print a;a=b;b=$0}'

Note that you might want to include a little more logic if you want
blanklines in there..  This doesn't store all of it in a file or in ram.


http://askubuntu.com/questions/475694/awk-command-to-print-all-the-lines-except-the-last-three-lines

On 2015-03-04 3:33 PM, Adam Thompson wrote:
> Like Tim said, you first have to know how many lines exist in the file
> before you can do anything other than stream processing.
> On moderately-sized inputs, "wc -l" works reasonably well. On large
> inputs, there's no way to do this efficiently unless you're willing to
> sacrifice accuracy.
>
> F=filename
> L=$(wc -l $F)
> head -n $(( $L - num_of_ignored_lines ))
>
> -Adam
>
> On March 4, 2015 2:36:24 PM CST, Kevin McGregor
> <kevin.a.mcgregor@gmail.com <mailto:kevin.a.mcgregor@gmail.com>> wrote:
>
>     Can someone help me out? I'm too tired to think straight.
>
>     Is there an easy/short way to get all BUT the last n lines of a
>     text file/input? All I can think of is reversing the input line
>     order and tail +n or something like that. FYI the input is not
>     very big.
>
>     Kevin