Re: tail +n does not work under Linux?

[Christophe LYON]

> > I am using coreutils-7.2, and I have just reproduced the issue with 
> > 7.3, under Linux RHEL 3 and 4.
>
> Also with Fedora 10's 6.12 package. The behavior change I think may have 
> been in 6.0 (it is probably in the changelog).

I do remember that change, but I also thought that it had been reverted 
a few releases later.

> > Curiously, it works OK under Solaris 8.
> Are you talking about GNU coreutils here, or the Solaris tail? If the 
> behavior is different for GNU coreutils, that is probably a bug.

Yes, GNU coreutils built under Solaris.

> > .... and tail -3 works.
> > Have I misunderstood the doc
> Yes.

> > or is it a bug?
> No, it is intended behavior.
>
>  From 'info tail':
>
>    For compatibility `tail' also supports an obsolete usage `tail
> -[COUNT][bcl][f] [FILE]', which is recognized only if it does not
> conflict with the usage described above.  This obsolete form uses
> exactly one option and at most one file.  In the option, COUNT is an
> optional decimal number optionally followed by a size letter (`b', `c',
> `l') to mean count by 512-byte blocks, bytes, or lines, optionally
> followed by `f' which has the same meaning as `-f'.
>
>    On older systems, the leading `-' can be replaced by `+' in the
> obsolete option syntax with the same meaning as in counts, and obsolete
> usage overrides normal usage when the two conflict.  This obsolete
> behavior can be enabled or disabled with the `_POSIX2_VERSION'
> environment variable (*note Standards conformance::).

But 'man tail' says:
       -n, --lines=N
              output the last N lines, instead of the last 10; or  use 
 +N  to
              output lines starting with the Nth

does it mean that '-n' is mandatory before a number? I interpreted it as 
 '-number'.

Christophe.