On 03/11/14 20:16, Dale Snell wrote: > On Mon, 03 Nov 2014 16:36:04 +0000 > Ralph Corderoy wrote: >> BTW, your mombog.mom had a blank line at the start and the comments >> were lines starting `\#' rather than `.\#'. One or the other might >> have an affect on your attempt at A3 in mom, I don't know. > > "\#" is a _groff_ comment,
Yes, but it's explicitly a GNU troff extension to standard troff grammar; it may not produce the desired effect, were you to process your input through any other troff implementation. The standard, and thus intrinsically portable, closest equivalent is `\"'; however, it is not entirely equivalent, since `\#' swallows the following newline, (at the end of the comment), whereas `\"' does not. (For a whole line comment, the portable equivalent to `\#' is `.\"'). > not mom's. Mom shouldn't care. If she > does, she needs to be chastised, but I think she's safe. The only > time I use anything different is when I want an "in-line" comment. > E.g., > > .MY_MACRO ARG ARG \" this is a silly example Here, you almost certainly don't want the comment to swallow the newline, so `\#' would surely be unsuitable. If you always use `\"' for comments, and always append them to lines which begin with a (maybe empty) request, you don't have to worry about the distinction. > As for the blank line at the top of the file, I don't think mom cares. > I just tried adding a blank line to one of my mom files, and there was > no change. Of course, I didn't have any PS or PDF images in it, so it > wasn't really a good test. In general, blank lines in troff input *are* significant; they induce a break, and introduce vertical white space in the output. At the start of a document, where space mode is inactive, you may not observe the effect, but relying on such quirks generally is inadvisable.