Hi Branden, On Thu, Oct 26, 2023 at 09:51:40AM -0500, G. Branden Robinson wrote: > At 2023-10-26T16:12:36+0200, Alejandro Colomar wrote: > > Regarding PP, LP, and P, what's the history of them? Why do we have > > the 3? I'm willing to reduce them to just one. > > I invite Doug McIlroy to go on record, but my surmise is that they were > introduced as crutches for people already familiar with ms(7). > > Doug's original man(7) (1979) didn't have `P`. But Unix System III > added it in 1980, and 4.3BSD followed suit in 1986. This information is > in groff_man(7). Was the original PP? > > In ms(7), `LP` sets a paragraph that is left-aligned, and `PP` sets one > with a first-line indentation. > > In man(7), all (ordinary) paragraphs behave analogously to ms(7)'s `PP`. > A first-line indentation is never used. > > My opinion is that one should use `P` exclusively for a few reasons. > > 1. Its name is short and it is frequently used. Huffman coding FTW. > 2. The existence of both `LP` and `PP` is difficult to rationalize to > anyone except a seasoned ms(7) author, of whom there are almost none > writing man(7) documents today. Still, compatibility with ms(7) would make it slightly easier to trasnfer learning from man(7) to ms(7), would one learn it. I know many other macros are incompatible in bad ways, but the less the better, no? Cheers, Alex > 3. It's been around long enough that everything supports it. `LP`/`PP` > have no measurable advantage in this respect. Anyone running early > BSD in 2023 has more interesting things to do than the composition > of legacy man pages. > > Incidentally, mm(7) would have already had a `P` macro as well by 1979. > Its call syntax is different (it interprets arguments; ms(7)'s and > man(7)'s "plain" paragraphing macros do not). Maybe this, and/or some > friction between Bell Labs Research and the constantly reconfiguring > series of departments dedicated to deriving revenue from Unix (and > troff) commercially accounts for man(7)'s omission of it. > > Nowadays, we can be confident that no loon is going to do something > crazy with mm's `P` macro such that it would trip up man(7) writers. > > <an evil grin spreads slowly across my face> > > Regards, > Branden -- <https://www.alejandro-colomar.es/>
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