Possible bug in tail(1)

[Matthias Apitz]

El día miércoles, septiembre 27, 2017 a las 12:58:28p. m. -0700, list at museum.rain.com escribió:

> Is it reasonable to expect that tail -r is reversable?  That is, should:
> 
> tail -r foo | tail -r
> 
> produce the same output as:
> 
> cat foo
> 
> for all text files foo?
> 
> The script below creates a file foo for which the above does not
> hold.

The essence of the issue seems to be if tail(1) is reading a file/stdin
or a pipe:

$ cat foor

3
2
1
$ tail -r foor
1
2
3

$ tail -r < foor
1
2
3

$ cat foor | tail -r
1
2

3



-- 
Matthias Apitz, ✉ guru at unixarea.de, ⌂ http://www.unixarea.de/  ☎ +49-176-38902045
Public GnuPG key: http://www.unixarea.de/key.pub
8. Mai 1945: Wer nicht feiert hat den Krieg verloren.
8 de mayo de 1945: Quien no festeja perdió la Guerra.
May 8, 1945: Who does not celebrate lost the War.
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