[RndTbl] Easy script question?

[Gilbert E. Detillieux]

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 at keizer.ca
> <mailto:robert at 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 at gmail.com <mailto:kevin.a.mcgregor at 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

-- 
Gilbert E. Detillieux		E-mail: <gedetil at muug.mb.ca>
Manitoba UNIX User Group	Web:	http://www.muug.mb.ca/
PO Box 130 St-Boniface		Phone:  (204)474-8161
Winnipeg MB CANADA  R2H 3B4	Fax:    (204)474-7609