Re: [Groff] underlining in nroff

[Mark Nudelman]

I'm sorry, I'm confused.  The screenshot you sent me seems to show exactly
what I would expect (except for the overstruck tabs, which I agree is a
bug).  In the "Spaces between words" part, the first line is displayed
completely in underline mode.  In particular, the spaces between the words
are in underline mode.  What did you mean when you said you get different
results?  In the "Underscores between words" part, the underscores are not
displayed in underline mode, but (probably) in bold mode.  Actually, as the
last screenshot shows, the bold underline looks nearly identical to the
normal underline, so it's hard to tell.

To clarify things, you can try this.  Set these environment variables to
printable strings like this:
 setenv LESS_TERMCAP_us '<U>'
 setenv LESS_TERMCAP_ue '</U>'
 setenv LESS_TERMCAP_md '<B>'
 setenv LESS_TERMCAP_me '</B>'
This will cause less to output these HTML-like strings instead of the escape
sequences it would normally use to enable and disable underline and bold
modes.  Then if you less your file, it will be easier to see exactly what
modes
are being used.
--Mark

----- Original Message -----
From: "Werner LEMBERG" <address@hidden>
To: <address@hidden>
Cc: <address@hidden>; <address@hidden>
Sent: Saturday, March 31, 2001 3:29 PM
Subject: Re: [Groff] underlining in nroff


>
> > An underlined space is indeed displayed as a space in underlined
> > mode.
>
> ???  I get different results.  Please look at the attached examples.
>
>   `lesstest.a.cat.png' shows some relevant ISO 6429 escape sequences
>   -- xterm is indeed able to display an underlined underscore (this
>   works with other X fonts also).
>
>   It looks like a bug concerning underlined tabs in
>   `lesstest.b.cat.png' ...
>
>   `lesstest.b.less.png' exhibits a bug in less (which I've already
>   reported) with tabs.
>
> > An underlined underscore would be treated the same way, except that
> > it just so happens that the bold attribute (overstriking a character
> > with itself) takes precedence, so an underscore overstruck with an
> > underscore is displayed as an underscore in bold, not underlined.
>
> But I don't get a bold underscore character (compare the bold
> underscore in `lesstest.a.cat.png with lesstest.b.less.png').
>
> > Back to (what I think was) the original issue, the problems you're
> > seeing are probably a result of different fonts displaying a bold
> > underscore differently.
>
> I don't think this is a font issue...
>
>
>     Werner
>


----------------------------------------------------------------------------
----


>
> Spaces between words:
>
> _T_h_i_s_ _i_s_ _a_ _t_e_s_t_.
> This is a test.
>
> Tabs between words:
>
> _T_h_i_s_ _i_s_ _a_ _t_e_s_t_.
> This is a test.
>
> Underscores between words:
>
> _T_h_i_s___i_s___a___t_e_s_t_.
> This_is_a_test.
>
>


----------------------------------------------------------------------------
----


>
> Here are some tests for the ISO 6429 Set Graphics Rendition command
>
> This is_a test.  0 default rendition
> This is_a test.  1 bold or increased intensity
> This is_a test.  4 singly underlined
>
>