Re: Bug#982208: coreutils: cat -E, --show-ends display strangely when CR (\ r) is included.

[Pádraig Brady]

On 07/02/2021 13:08, KenichiroMATOHARA wrote:
> Package: coreutils
> Version: 8.32-4+b1
> Severity: minor
>
> Dear Maintainer,
>
> When I create a text file with a newline code of "\r\n" and
> `cat` with the `-E, --show-ends` option, "$" is displayed at
> the beginning of the line.
> When `-A, --show-all` is used, it looks normal.
>
>
> - Create a file for \r\n
> > $ echo 'foo
> > >      $ od -c dos.txt
> > 0000000   f   o   o  \r  \n  \t   b   a   r  \r  \n
> > 0000013
> >    bar' | tr '\n' '\r\n' > dos.txt
>
> - `-E, --show-ends` option
> > $ cat -E dos.txt
> > $oo
> > $       bar
> > $ cat -nE dos.txt
> > $    1  foo
> > $    2          bar
>
> - `-A, --show-all` option
> > $ cat -A dos.txt
> > foo ^M$
> > ^Ibar^M$
> > $ cat -nA dos.txt
> >       1  foo^M$
> >       2  ^Ibar^M$

I agree the current behavior is less than useful because:

  * \r\n is common a line end combination
  * catting such a file without options causes it to display normally
  * overwriting the first char with $, loses info

I propose to change the upstream coreutils project
as per the attached, to extend the --show-ends option
to show \r as ^M when the following character is \n.

thanks,
Pádraig

cat--show-ends.diff
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