\newcommand{\bfig}{\begin{figure}\begin{center}} Oh :-(

@DavidCarlisle Nice to hear from Morten ;)

Quack!

@PauloCereda Quack!

@JosephWright ooh a duck

@JosephWright I did prod sleeping giants with a stick:-)

@DavidCarlisle ooh a pointed stick

@DavidCarlisle Frank wins the 'first new bug' competition ;)

@JosephWright with a documented feature from 1993:-)

@DavidCarlisle ooh

Don't use footnotes in your books, Don.
\author JILL ^{KNUTH} (1962)

@DavidCarlisle It would be awesome if that citation could be enclosed in a \footnote. :)

@PauloCereda LOL! By the way, qua qua qua. P.S. = don't talk about soccer today! :)

@CarLaTeX nope. :)

@DavidCarlisle: how do you like my snake skills in my answer? :)

@PauloCereda Is asking how to do a specific calculation based on the content of a page from within LaTeX not related to (La)TeX?

@TorbjørnT. Yes, that one. :) I decided to give it a try just for fun. :) The question is really off-topic.

@TorbjørnT. From within LaTeX is a different matter. :)

@PauloCereda Yes, and that is what the OP is asking for I think, even if it isn't very clear.

@PauloCereda (Of course, adding the information to the page means that a smaller part of the page is empty, so your calculation is not accurate at the moment.)

@TorbjørnT. In that case, I think it should be rewritten to clarify that. From my take, I understood the opposite.

@TorbjørnT. Sorry, I don't follow. :(

@TeokanDuranDemircan why would you ever want to do this? using some bitmap library is the answer as you showed and as @PauloCereda showed can be scripted in various ways is the answer (tex has no information about the glyph shapes so the question is unrelated to tex)

@DavidCarlisle Perhaps that could be an answer, as @TorbjørnT. mentioned. The fact that TeX has no information about the glyph shapes might me a valid answer IMHO. :)

@PauloCereda The OP wants to have "Some text bla bla. This page is X% empty" on the page. Your calculation just includes the "Some text bla bla" part.

@TorbjørnT. Ah I see what you mean now, thanks. :) However, this just seems to be an egg-chicken problem to me. :)

@DavidCarlisle No, as @PauloCereda says, the answer to the question is then "You can't do that with TeX".

@TorbjørnT. actually I have a perfect tex based solution, using a package I wrote. (much better than @PauloCereda's attempt)

@TorbjørnT. We could have a footnote saying that the percentage might not be accurate due to that additional text. And this footnote. And the note about the footnote.... ooh I like this idea!

:D

@DavidCarlisle you are envy of my snake

\color{white} this page is 100\% empty

@TorbjørnT.: I removed my off-topic comment, thanks for the remark. :)

@DavidCarlisle ooh

@PauloCereda Or a problem of convergence. The OP did some manual iteration as you can see from the answer.

@TorbjørnT. Ah yes, that too. :)

@JosephWright: got a notification from this app being in the Fedora COPR repos. Do you know about it? molsketch.sourceforge.net

@PauloCereda stick to MS paint

@DavidCarlisle ooh :)

@DavidCarlisle So slow with Arabic. ;-)

In KOMA-script, is there a nicer way to add a period after every paragraph title than redefining \paragraph?

@PauloCereda Know the name

@PauloCereda Still rubbish ...

@egreg السلامة اولا interesting approach, to redefine just the end code of an environment

@DavidCarlisle Yes, that's quite interesting.

@DavidCarlisle They want just \endlist and not \if@twocolumn \else \endquotation \fi

@egreg \@dblarg question:-)

@DavidCarlisle OP has no taste

@egreg just an appreciation of natural justice:-)

@JosephWright oh :)

@TorbjørnT.: nice code! So far, I haven't seen any problems with it. :) Please post it!

From a \listfiles output: newlfont.sty 1998/08/17 v2.2m Standard LaTeX package

@egreg it's good to use standard packages

@DavidCarlisle :)

@DavidCarlisle And, of course, type1cm

@PauloCereda Nah, just add it to your answer, if you like.

$ pdflatex pp692
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017) (preloaded format=pdflatex)
 restricted \write18 enabled.
entering extended mode
(./pp692.tex
LaTeX2e <2017-12-01> patch level 99
Babel <3.14> and hyphenation patterns for 84 language(s) loaded.
(/home/davidc/texmf/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/home/davidc/texmf/tex/latex/base/size10.clo)) (./pp692.aux)Segmentation fault (core dumped)

@JosephWright @egreg ^^

I used gdef instead of xdef by mistake so the trace looks like

\zzp ->\the \numexpr \zzp +1\relax
{\the}

\zzp ->\the \numexpr \zzp +1\relax
{\the}

\zzp ->\the \numexpr \zzp +1\relax
{\the}

\zzp ->\the \numexpr \zzp +1\relax
{\the}

\zzp ->\the \numexpr \zzp +1\relax
{\the}

but it's not supposed to segfault is it?

Nice! Source?

@egreg simplified it to

\def\zz{0}
\def\zz{\the\numexpr\zz+1\relax}
\zz
\bye

what do you get on the mac?

@egreg see my latest answer for the version that doesn't seg fault:-)

@HaraldHanche-Olsen Same here

@DavidCarlisle This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017) (preloaded format=pdftex)

@DavidCarlisle I guess it only segfaults with a new format?

@UlrikeFischer new added feature:-)

@UlrikeFischer nope same in plain. I suppose it's cygwin :(

@HaraldHanche-Olsen thanks

@DavidCarlisle ! TeX capacity exceeded, sorry [input stack size=5000]

@egreg I get segfault with all of etex,xetex,pdftex,luatex with 2017 and 2016 binaries

@DavidCarlisle Ah yes could not be latex ;-). Doesn't segfault here.

@DavidCarlisle But you're using a very reliable OS

@TorbjørnT. Roger. :) I updated the code a bit. Great job!

@JosephWright -- do you know whether, if two questions, by two different posters, are merged, the person who posted the "removed" question will get pinged? see this question to see why i'm asking.

@barbarabeeton Don't think they are

@barbarabeeton On the meta question, the model from the word go is that a 'good' question can have an answer ....

@DavidCarlisle I see Frank is getting into this GitHub business: have to see how Javier gets on (or perhaps Morten!)

What is the best way to estimate the number of lines a parbox produces? Dividing the total height through the \baselineskip rounded up seems to give a good estimation but I'd like the result to be as precise as possible (with reasonable effort).

@Skillmon ?

@Skillmon define "line" if the parbox has \parskips, or graphics or displayed equations? total height / \baselineskip is possibly the only definition that ther is?

@DavidCarlisle and if there is only text?

@Skillmon if there is only text and you know the height and the baselineskip then the number of lines is one divided by the other (although of course if the text on the inside uses \footnotesize or some such you need the right \baselineskip

@DavidCarlisle if I use \baselineskip in the same group it should be correct, doesn't it?

@Skillmon well you haven't really shown the context but if you only have the parbox as a "black box" you can not reliably tell what's inside it or what fontsize or baseline it has.

@DavidCarlisle then the user is at fault :)

@Skillmon In my experience, that is always the case.

@DavidCarlisle nah, I once found a bug or was it a hidden feature?

@Skillmon feature (but even if it was a bug, it would have been your fault for uncovering it)

@DavidCarlisle I happen to find minor bugs frequently (which are totally my fault for uncovering them). Most of them are in websites which try to set the colour of an input field but don't set the font colour, which is particularly annoying if your default font colour happens to match the defined background :(

@AlanMunn -- regarding my meta questino, the problem is that the only possible answer at the moment is that there is no good answer. it's explained in the comments to one of the questions. i really hate to make that an "answer, but do you think i should?

@barbarabeeton Well the answer that I would give would be "here's how to fix it using titletoc (or tocloft) but if you're submitting to an AMS publication, don't." :)

@AlanMunn -- i don't actually have an answer with titletoc or tocloft. we haven't had good results with thise when we tried them here, but that's a long time ago. i guess i'll try again to figure something out that dioes't foul up other things.

@barbarabeeton Ah, ok. I was just assuming that the problem wouldn't be too hard to solve with one of those packages. But I know very little about the AMS classes.

@egreg you're never there when you are needed tex.stackexchange.com/a/400862/1090

@barbarabeeton link?

@DavidCarlisle Easy task even for you!

@barbarabeeton Now I see the problem. Certainly titletoc out of the box doesn't work.

@barbarabeeton What about this patch?

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