Re: sort : skipping "header" row(s) - possibile new command line option?

[Leslie S Satenstein]

Given the discussion of head, tail within sort, how about drop.  Drop ±n to 
drop the first ±n lines. If negative, drop the last n lines (All done before 
the sort). Regards 
 Leslie
 Mr. Leslie Satenstein
Montréal Québec, Canada


 
      From: Davide Brini <address@hidden>
 To: address@hidden 
 Sent: Wednesday, November 19, 2014 4:04 AM
 Subject: Re: sort : skipping "header" row(s) - possibile new command line 
option?
   
On Wed, 19 Nov 2014 15:21:35 +1100, Bradley Dean <address@hidden>
wrote:

> It's often possible to do this by looking at the data twice (once to
> grab the header, once to sort) - either by dumping to a file or by
> running the generating command twice.
> 
> For example - take some_command which outputs space-delimeted data with
> 1 header row and a fourth numeric column I'd like to sort on:
> 
>  some_command > templog; head -1 templog; tail -n +2 templog | sort -n
>  -k 4
> 
> I think it would frequently be handy to be able to just ask sort to keep
> the header rows aside - especially when doing things like running the
> sort inside a "watch" loop where you'd like to be able to come back to
> it over time and see what each column is.

I'm not against having an option, but in cases like this you can do

some_command | { IFS= read -r header; echo "$header"; sort -n -k4; }

can be generalized to N header lines with a read loop, eg for 3 lines:

some_command | { n=0; while [ $n -lt 3 ]; do IFS= read -r header; echo
"$header"; ((n++)); done; sort -n -k4; }



-- 
D.