chasma (03/08/83)
Recently, I tried using the .rd control in an nroff source file and got some unexpected results: it seems to work as described in the manual, *except* that the text typed from the terminal for insertion to the document is not echoed on the terminal. I believe this is the first time anyone at this installation has tried to use .rd and am wondering if this is a problem with nroff in general, or a bug in our installation. Any help/ comments/sympathy/etc will be appreciated. -Charles Marsh (decvax!ittvax!ittapp!chasma)
jrc@rlgvax.UUCP (Jim Chapell) (07/24/85)
Re: nroff, how come
.sp 4/2+1
spaces 1 line whereas
.nr s 4/2+1
.sp \ns
spaces 3 lines?
Or is this a local bug?
--
Jim Chappell
CCI, Reston, Va
{seismo | allegra | ihap4} !rlgvax!jrc
703-648-3319jaap@mcvax.UUCP (Jaap Akkerhuis) (07/30/85)
In article <707@rlgvax.UUCP> jrc@rlgvax.UUCP (Jim Chapell) writes: > > Re: nroff, how come > .sp 4/2+1 > > spaces 1 line whereas > .nr s 4/2+1 > .sp \ns > > spaces 3 lines? > The answer is of course in the Nroff/Troff reference manual (Page 9, alinea 1.4 \fINumerical expressions\fP). "In the present of default scaling, ..." etc. The commands .nr s 4/2+1 .sp \ns should be read as: .sp (4u/2u+1u)*1v giving a spacing of 3 lines (default scaling is `v'), while .sp 4/2+1 specifies a spacing of 42 units, rounded to 40 units (==\n(.v) as shown by .nr a 4v/2v+1v .nr b \na/\n(.v .ie \nb>1 .tm \na units rounded to \nb lines of spacing .el .tm \na units rounded to a single line of spacing .ab "End of demonstration"
kolstad@convex.UUCP (08/02/85)
you asked: why does .sp 4/2+1 not do the same as .sp 3 (in essence, anyway) The answer is: nroff (and troff) are always trying to be helpful and give you default units for things. When you say ".sp 1" then nroff (and troff, too) say: ``well, he doesn't want to space 1 UNIT (maybe 1/432" or 1/300") he really wants to space 1 LINE (a VERTICAL UNIT -- 1v)''. Now, this is all well and good for things like ".sp 1+1" which translates to ".sp 1v+1v". The trick comes when you do something like ".sp 4/2+1" which good old nroff (and troff, too) changes to: .sp 4v/2v+1v which is of course: .sp 2u+1v which is a single space (or close enough)... The solution to your problem is to remember two things: (a) nroff & troff's only goal in life is to screw you (b) when in doubt, ALWAYS SPECIFY UNITS. The following seems to work just fine: .sp 4v/2u+1v which is probably what you wanted anyway. Your friend in text processing, Rob Kolstad CONVEX Computers 214-952-0351