bug#39951: tail -n +NUM is not working properly

[Bernhard Voelker]

On 3/6/20 10:42 AM, Dimitris Moraitidis wrote:
> Hey there,
>
> tail -n + NUM does not return the desired output. +NUM starts from the top
> of the file, not from the bottom.
>
> So for example, given the following file:
>
> > this
> > is
> > an
> > example
> > file
> > each
> > word
> > represents
> > a
> > line
>
> and executing tail -n +3 example, I am getting
>
> > example
> > file
> > each
> > word
> > represents
> > a
> > line
>
> instead of
>
>
> > this
> > is
> > an
> > example
> > file
> > each
> > word
>
> I am using *tail (GNU coreutils) 8.28 *in latest ubuntu 18.04 LTS
>
> Thanks in advance for looking into this :)

Isn't this exactly what tail(1) is support to do when the user explicitly
passes the '+' sign to the number?

  $ tail --help | grep -A1 -- --lines
    -n, --lines=[+]NUM       output the last NUM lines, instead of the last 10;
                               or use -n +NUM to output starting with line NUM

Also POSIX says so:
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/tail.html

Have a nice day,
Berny