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Re: RFC: Making -B and -T work better on 8-bit encodings

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Brad Gilbert
July 8, 2014 19:44
Re: RFC: Making -B and -T work better on 8-bit encodings
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On Tue, Jul 1, 2014 at 7:25 AM, David Cantrell <> wrote:
> On Fri, May 02, 2014 at 02:28:48PM -0600, Karl Williamson wrote:
>> I also think that Vertical Tab and Form Feed are so infrequent that they
>> should be counted as non-text (currently VT is non-text, but FF is)
> Consistency is good, and while FF is rare, it's nothing like *as* rare
> as VT. I know that I have some documents that contain it, because I
> remember deliberately putting them there, but I've only ever seen VT in
> deliberately pathological test cases.
> So I vote for FF being treated as text.

Its similarity to LF and CR makes me believe FF could be dealt with the same
as LF and CR. It's use back in the days of DOS was as a simple way to start
a new page. You could run something like `copy example.txt LPT1` and the
printer would skip to the next page upon receiving a FF.
FF would basically do a CR followed by enough LFs to get to the next page.

On Epson dot-matrix printers you would have to set up vertical tab
positions with ESC codes before you used VT.
( similar to how you would set tab stops on a typewriter. )
Which makes me believe it was used for filling out preprinted forms.
Very useful for making duplicates with carbonless copy paper.

Since TAB has come to mean 8 spaces I think it could be considered
as text. I don't think that VT should though; as it is very specific to
the hardware you are communicating with.

>>                                                      ESC currently is
>> considered text, and my patch retains that, as it is relatively commonly
>> used in rich text files.
> RTF isn't really plain ASCII text so I think that's a bad argument. ESC
> isn't printable so I'd love to see it considered to be un-text. However,
> I think that I'd again go with consistency and so hold my nose and treat
> it as text - unless it becomes un-text everywhere else.

The last time I used ESC was when I was directly controlling my
dot-matrix printer. Where it is used as an indicator that the bytes
that follow are used to change a mode. Such as setting it
into graphics mode. I think it should be considered in the same way
as DC1 .. DC4, and BEL.
( Some of my first Perl programs were created to play around
with my dot-matrix printer )

> --
> David Cantrell | Pope | First Church of the Symmetrical Internet
>     fdisk format reinstall, doo-dah, doo-dah;
>         fdisk format reinstall, it's the Windows way

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