On 26/10/15 13:12, Dorai Sitaram wrote: > Incidentally, is there a way to tell from inside a document whether > it is being processed by pdfroff or groff -Tps? In both cases, the > string register .T is 'ps'.
Not really; pdfroff is just a shell script, which runs groff -Tps multiple times, (to resolve internal pdfmark references), until the layout stabilizes, then pipes the resultant PostScript output through gs, to generate PDF output. You might infer use of pdfroff from the existence of a register called PHASE, (which will have a value of 1 when compiling a relocatable TOC, and 2 in the final document body generating pass), but that's hardly exclusive to pdfroff.
