shell pipeline to reverse the order of lines.

[John F Haugh II]

In article <2763 at kraftbus.cs.tu-berlin.de> net at opal.cs.tu-berlin.de (Oliver Laumann) writes:
>In article <19074 at rpp386.cactus.org> jfh at rpp386.cactus.org (John F Haugh II) writes:
>> % tail -r /etc/passwd
>> usage: tail [+|-[n][lbc][f]] [file]
>> 
>> [..] Watch out for those non-standard features.
>
>Considering that the `tail' command under vanilla BSD (at least 4.2 and
>4.3 BSD) has this `feature' I wouldn't call it non-standard.  After all,
>`tail' is a BSD command.

What would you prefer to call a feature which does not exist on all
systems that have the command?  What would you prefer to call a
command which may not exist on all systems?  How about ... a non-
standard feature on a non-standard command?

As for being a ``BSD'' feature, I've yet to see a UNIX system without
the command, and that includes my 9 year old XENIX system, and the 10
year old USG 5.0 system before that.  My ``Release 5.0 UNIX System
User's Manual'', which used to be dated July 1981 (or so, I forget)
gives the same 'tail [ +/-[number][lbc[f]]] [file]' usage I gave above.

The definitive test of BSD-ness was to drag out the 4.3-reno freed
sources tape and see if there was a tail there.  Nope, no tail.

Perhaps you have tail confused with head, which =is= a BSD command.
-- 
John F. Haugh II                             UUCP: ...!cs.utexas.edu!rpp386!jfh
Ma Bell: (512) 832-8832                           Domain: jfh at rpp386.cactus.org
"I've never written a device driver, but I have written a device driver manual"
                -- Robert Hartman, IDE Corp.