Re: [Groff] conditionals

[Larry Kollar]

Larry McVoy wrote:

> .if !\n[EULA]=0 \{\
> .if !\n[EULA]=1 \{\
> .if !\n[EULA]=2 \{\
> .if !\n[EULA]=3 \{\
> .ab No EULA defined
> .\}
> .\}
> .\}

If I remember correctly, EULA will return 0 if not previously  
defined, so you'll never reach the abort. You can do this in one line:

.if !rEULA .ab No EULA defined


> Anyway, the doc is full of
>
>         .if \n[EULA]=1 \{\
>
> etc.
>
> What I would oh-so-love to be able to do is
>
>         .if \n[EULA]=1 || \n[EULA]=3
>
> I wandered through the groff docs and didn't see any way to do that.

It's defined in groff(7), and in sec. 5.3 of the texinfo doc. Logical  
OR is a colon:

.if \n[EULA]=1:\n[EULA]=3 \{\

It would have been interesting to ask Joe O why a colon instead of a  
pipe here. Anyway, I use constructs like this all the time in my docs.


Hope this helps,

        (the other) Larry