[Groff] Re: underlining in nroff.

[Ralph Corderoy]

Hi,

Sorry, but dragging up this old thread...

> currently, the underlining commands .ul and .cu does exactly the same
> in nroff mode of gtroff. This is incorrect, of course. Nevertheless,
> I have some questions how underlining works in Unix nroff and I ask
> for help in answering this. 
> 
> . What is the default underlining mode if I select an `italic' font 
>   (\fI) in nroff? .ul or .cu? 

AIX 3.2.5's nroff on

    \fI1.1 Section Heading\fP

    .cu
    1.1 Section Heading

    .ul
    1.1 Section Heading

gives

    <1>.<1> <Section> <Heading>

    <1.1 Section Heading>

    <1>.<1> <Section> <Heading>

where <> marks the underlined text.  So \fI is .ul.

But, you see how the `.' in 1.1 isn't bold with .ul?  _Introducing Unix
System V_ says .ul only underlines alphanumeric characters and you need
.cu to give continuous underline on all characters, including space.
That seems to match the `.' not being bold.

With `groff -Tascii' I get the same output for all three

Furthermore, it explicitly says troff (meaning ditroff) is the same as
nroff in its `alphanumeric only' treatment but that the difference is
normally only noticable when characters such as `[' are involved
because the italic version is clearly different.  `groff -Tps' again
gives italics for all characters with .ul.

This is really just to throw up more historical material and testing
for discussion rather than a firm view as to what should be done.


Ralph.