AW: is there a bug in tac when it interpret REGEXP for separator

Hello Bob,

thank you for answer. OK. I've talk with other unix gays and see mistakes in
my tests. The dot is a REGEXP for all sign except(!) newline and the REGEXP
[^.] means every sign except dot.

Now I'm searching for a REGEXP that means all signs (incl. newline). Or what
is the way to turn a datastream with tac?

Winfried


-----Ursprungliche Nachricht-----
Von: Bob Proulx [mailto:[email protected]]
Gesendet: Mittwoch, 19. Mai 2004 17:08
An: [email protected]
Cc: [email protected]
Betreff: Re: is there a bug in tac when it interpret REGEXP for
separator


[email protected] wrote:
> Hallo,

Thank you for your report.  But I had difficulty understanding what
you were intending.  Perhaps others on the mailing list did as well.
Perhaps you could clarify with more information to the mailing list.

> I want to turn round a datastream with tac, not every line but every
> sign.

"every sign"?  Could you provide the output you think you should be
getting in that case as well?

> Now my tests:
>
> wim@g8ser001:~/tmp> echo -e "abbc\ndef" | tac -rs \.
>
> fe
> dcbbawim@g8ser001:~/tmp>
> this ist wrong.

Check your command with echo.  The backslash here is not needed.  It
is not a shell metacharacter and needs no escaping.

  echo tac -rs \.

What is the output of this command?

  echo -e "abbc\ndef" | tac -rs \. | od -c

What output are you expecting?

> wim@g8ser001:~/tmp> echo -e "abbc\ndef" | tac -rs \[^.\]
>
> fed
> cbbawim@g8ser001:~/tmp>

And again:

  echo -e "abbc\ndef" | tac -rs \[^.\] | od -c

What output are you expecting?

> this is right but I dont understand how tac interpret the REGEXP because
> ^ in grep is to negate . When tac the ^ to interpret as linestart then
> must this also work:
>
> wim@g8ser001:~/tmp> echo -e "abbc\ndef" | tac -rs \[.^\]
> abbc
> def
> wim@g8ser001:~/tmp>
> it dont work.
>
> wim@g8ser001:~/tmp> tac --version
> tac (textutils) 2.1

Your version of texutils is very old.  Perhaps you would consider
updating?

  ftp://ftp.gnu.org/gnu/coreutils/coreutils-5.2.1.tar.gz
  ftp://ftp.gnu.org/gnu/coreutils/coreutils-5.2.1.tar.bz2
  (coreutils is the union of fileutils, textutils, and sh-utils)

Bob