TeX, LaTeX and Friends

7:35 AM

In the LuaTeX manual, the possible settings for status.shell_escape are given as:

> 0 means disabled, 1 means anything is permitted, and 2 is restricted

If I do not set -shell-escape on the command line, I get 2. If I set it, I get 1.

Under what circumstances would I get 0?

root@orwell:/home/faheem# ls -lah /usr/share/texlive/texmf-dist/web2c/texmf.cnf /usr/share/texmf/web2c/texmf.cnf
-rw-r--r-- 1 root root 35K Jul 10 06:39 /usr/share/texlive/texmf-dist/web2c/texmf.cnf
lrwxrwxrwx 1 root root  40 Jul 10 06:39 /usr/share/texmf/web2c/texmf.cnf -> ../../texlive/texmf-dist/web2c/texmf.cnf

I'm not sure why that symbolic link exists. But in any case, is it ok to edit that config file manually?

Ulrike Fischer

8:21 AM

@FaheemMitha no, if you want to change a texmf.cnf setting, do it in a local texmf.cnf.

Faheem Mitha

8:47 AM

@UlrikeFischer Oh. Ok.

David Carlisle

10:21 AM

@FaheemMitha luatex is same as pdftex and has options shell-escape, no-shell-escape and shell-restricted corresponding to the three interger values

Paulo Cereda

@DavidCarlisle ooh nonclassical logic

David Carlisle

@PauloCereda never exclude the middle

Paulo Cereda

@DavidCarlisle bah what three-valued logic has ever done for us?

Besides a wacky balanced ternary computer.

Ternary computer

A ternary computer (also called trinary computer) is a computer that uses ternary logic (three possible values) instead of the more popular binary system ("Base 2") in its calculations. == Types of states == Ternary computing deals with three discrete states, but the ternary digits themselves can be defined in different ways, according to Connelly: Unbalanced Trinary – {0,1,2} Fractional Unbalanced Trinary – {0,1/2,1} Balanced Trinary – {-1,0,1} Unknown-State Logic – {F,?,T} Trinary Coded Binary – {T,F,T} == History == One early calculating machine, built entirely from wood by Thomas Fowler in...

David Carlisle

@PauloCereda the three main logical values are true, false, fear and surprise

6

Paulo Cereda

@DavidCarlisle LOL

@JosephWright ^^

Paulo Cereda

10:39 AM

@DavidCarlisle l3build-inquisicionespanola.lua

3

Joseph Wright

@PauloCereda We should add that ;)

Paulo Cereda

@JosephWright going to experimental. :)

Faheem Mitha

11:42 AM

@DavidCarlisle Is this documented in the PDFTeX manual? Though if so, I'm not even sure what that manual is.

TeXnician

@FaheemMitha pdftex --help shows the options and section 4 of the manual (texdoc pdftex).

Faheem Mitha

@TeXnician Oh. Thank you very much.

David Carlisle

12:04 PM

@FaheemMitha as @TeXnician just said:-)

Faheem Mitha

@DavidCarlisle Right. Thanks.

Faheem Mitha

1:01 PM

I just received an email from Andreas to say that he fixed that pdfpages issue. How quickly would updates to a package like pdfpages propagate to TeX Live?

Ulrike Fischer

@FaheemMitha when the author sent it to ctan it takes one or two days.

Faheem Mitha

@UlrikeFischer Sure. I meant, after that.

Since clearly not everything in CTAN gets into TeX Live.

Ulrike Fischer

@FaheemMitha as long as there is no problem with the licence it is added. Pdfpages is already in texlive so the update will be fast.

Faheem Mitha

@UlrikeFischer Oh? I thought CTAN was huge.

David Carlisle

1:17 PM

@FaheemMitha packages that are already in texlive normally get updated within a day of being updated at ctan (plus however long it takes your mirror to sync) but it does require Karl (usually) to do the update so occasionally he gets busy

David Purton

@Sebastiano We have great beaches! 20 mins from CBD, long long sandy, beautiful clean clear warm water since Adelaide is on a gulf (this also means hardly any sharks!), and we are small city, so not too many people. We're not tropical, so no crocodiles or stingers to kill you either. No surf though… though that goes both ways, surf beaches in Sydney are super dangerous, but Adelaide beaches are very safe and have no waves.

Faheem Mitha

@DavidCarlisle Ok. Though I use the Debian TeX Live packages, and those will certainly take a while to update.

David Carlisle

@FaheemMitha in that case s/Karl/Norbert :-) and of course it needs to go to upstream texlive first

David Purton

@FaheemMitha I have good success setting up a ~.texmf and using tlmgr to install just one package temporarily when I really need an update. (just have to remember to remove it later.)

Faheem Mitha

@DavidPurton Thanks for the suggestion.

On a related topic, does Debian packaging exist for an individual CTAN package? Or a template for it?

Current Debian TeX Live packages are still those of 5th June 2019.

David Carlisle

1:22 PM

@FaheemMitha I thin debian bunch together multiple texlive packages but I don't know the details, although you can use (a version of) tlmgr update even with debian as far as I understand

Faheem Mitha

@DavidCarlisle Debian packages multiple TeX Live packages in a single binary in general, but I don't know the details either.

I think the Debian packages offer some limited compatibility with tlmgr, but I've never tried it.

Paulo Cereda

@DavidCarlisle meanwhile, we have an updated TL. :)

David Purton

@FaheemMitha I think every TeXLive package name is listed in the description of the Debian package, so you can find the relevant Debian package with apt-cache search pdfpages.

Faheem Mitha

@DavidPurton Do you use the Debian packages too?

David Purton

@FaheemMitha yep.

Faheem Mitha

1:25 PM

@DavidPurton Sure.

@DavidPurton Oh. Glad to "meet" someone else who does. Does everyone keep telling you to use the upstream packaging?

David Purton

The biggest problem is that there is a massive download every month or two when TeXLive updates…

And some of the packages are huge.

Faheem Mitha

@DavidPurton Norbert doesn't update that often, though. Unless I'm missing something.

@DavidPurton Why is that a problem on modern fast connections?

Like I said above, last update 5th June.

David Purton

It takes a long time to install them. I have a fast connection and it only takes a few mins to download. But on my old computer it takes ages to install. And it was trying to install one of the big font packages that killed my computer recently :(

Faheem Mitha

@DavidPurton Hmm.Do you have SSDs?

David Purton

Yep

Old Macook Air

MacBook

Paulo Cereda

1:29 PM

@DavidPurton ooh komputer konnection for koalas :)

Faheem Mitha

Ah. Apple.

David Purton

It has a lot of problems with Linux. But new computer arrives this week!

Faheem Mitha

@DavidPurton New Apple? Or New Non-Apple?

David Purton

Stuck on Mac OS for the moment. Stupid OS

Not Apple. New Macs are impossible (basically) to run Linux on

Faheem Mitha

@DavidPurton You're in AU? Do you use that internet provider everyone loves to hate? Telstra, I think it is.

Paulo Cereda

1:31 PM

@DavidPurton I think it's quite the opposite, to be honest. :)

@DavidPurton in a year or two, my iMac will run Linux. :)

Faheem Mitha

@DavidPurton Really? Why?

David Purton

@PauloCereda Not laptops.

Paulo Cereda

@DavidPurton well, I had an old (mid 2007) Macbook and that's really a PITA to install Linux.

David Purton

@PauloCereda The new laptops have too much unsupported hardware. Even the trackpad and keyboard does not work well

Paulo Cereda

@DavidPurton ouch, sorry to hear. I had problems with a wireless card in the past, so I can relate. :)

David Purton

1:37 PM

@FaheemMitha No. Much too expensive :). I use a subsidiary of one of the other major players (Internode owned by iiNet).

Faheem Mitha

@DavidPurton Oh. How is it?

David Purton

I do have fibre to my house though :). We snuck in before the government realised that doing this for everyone was going to be crazy expensive

Faheem Mitha

Is fiber better than regular DSL or cable?

David Purton

@FaheemMitha Excellent. I only pay for 50 Mb connection, but it's very reliable and consistently quick even in peak times. Much better than DSL. DSL relies too much on copper which stops working every time it rains and the pits fill up with water…

Faheem Mitha

@DavidPurton The MTNL DSL I was using was very unreliable. The Airtel DSL I'm currently using is much more reliable, though not perfect. Are you saying it is just better technology?

David Carlisle

1:41 PM

@FaheemMitha fibre/cable is just a name difference isn't it?, when I switched from ADSL or fibre to the house my speed went from 1-2 Mbs (or less when windy) to 50Mbs (and I could have up to 900Mbs if I paid more)

Faheem Mitha

I've been hearing noises about fiber here for years, but nothing has come from it.

David Purton

In Australia they are rolling out a a brand new network with optical fibre cable.

Initially this was going to go to every premesis

Faheem Mitha

Though I just got a text message about Jio Fiber just this afternoon.

David Purton

and that's what I have

Faheem Mitha

@DavidCarlisle from ADSL to fibre to the house?

David Purton

1:43 PM

Now they are just running it along the street and using exisiting copper or cable for the last few metres

David Carlisle

@DavidPurton yes that's what I have here, I suppose cable could mean an older technology, marketing types tend to use meaningless things like "super fast broadband" so impossible to tell what they are offering without diggiging deeper:-)

Faheem Mitha

@DavidPurton 50 Megabits per second? If so, that's not exactly slow.

@DavidCarlisle By cable here I mean whatever is used for cable TV.

David Purton

@FaheemMitha It's fine for me. I can get 100Mb/s

Faheem Mitha

I'm not sure what that technology is.

@DavidPurton Right, but you mean megabits per second, right?

David Carlisle

@DavidPurton yes the main national provider (BT) runs fibre to the cabinet and then uses existing telephone connection to the houses but they were never going to connect us at all ("not economically viable") so the village arranged a private company that specialises in connecting rural villages, they lay the cable so currently we have no choice of internet provider but it's many times faster (and same speed upload as download)

David Purton

1:48 PM

@FaheemMitha yep. So actual speeds are around 4-6 MB/s

David Carlisle

@FaheemMitha yes

@FaheemMitha with ADSL running over copper phone wires the system nominally supported 8Mb/s download (and <1Mb upload) but actually never got more than 2Mb/s and if it was windy connection speed would decrease or break altogether (a lot of wire stretched on poles over a lot of fields....) but with fibre it is all underground so unaffected by wind and you get whatever speed you want basically (I take the minimum which is 50Mb/s in both directions)

Ulrike Fischer

@DavidCarlisle did you see? texlive will introduce version numbers in the packages.

David Purton

@DavidCarlisle In Australia we usually use cable to refer to the HFC cable networks used for Pay TV. The use optical fibre, but then the last leg is coaxial cable. The new internet network is using this last coaxial bit if it's already present, or copper if it's already present. New housing developments might still be getting optical fibre to the premises, but not exisiting houses now. Of course if you live in a remote area, all the governments promises have come to nothing :)

David Carlisle

@UlrikeFischer yes (although not sure what it affects to be honest) if you only ever use tlmgr update --all and never need to roll back individual version, I assume it doesn't have any visible effect at all?

Ulrike Fischer

@DavidCarlisle I hope. But Karl ended the message with "Good luck to us all" ;-)

David Carlisle

2:01 PM

@DavidPurton never had cable tv:-) (and here we don't even have street lights so I thought we'd never get reliable broadband at all, but this gigaclear company more or less do what they say and connect up rural villages so long as you can get 1/3 of houses to express an interest) worked for us.

egreg

@JosephWright Just for a check: next meeting is on Friday?

David Purton

@DavidCarlisle oh nice. Our problem here is that Australia is big and mostly sparsely populated. So outside of major cities, things are pretty terrible and rely on wireless connections.

David Carlisle

@DavidPurton yes Souldern wouldn't count as a major city (population ~200 :-)

@egreg yes

Ulrike Fischer

@egreg yes, and if I understood Joseph correctly at the same time.

egreg

@DavidCarlisle OK!

Paulo Cereda

2:11 PM

@UlrikeFischer ooh same time

Ulrike Fischer

2:35 PM

@DavidCarlisle I have been looking at the colortbl/bidi lualatex problem github.com/latex3/babel/issues/28. It looks as if an additional box solves the problem. Could one sneek this in?

\documentclass[12pt]{book}

\usepackage[bidi=basic,layout=lists]{babel} \babelprovide[import=ar,mapdigits,main]{arabic}
\babelfont{rm}{Amiri}
\usepackage{colortbl}
\begin{document}

اللغة العربية

\begin{tabular}{c} اللغة العربية\ \end{tabular}

\begin{tabular}{c} \hbox{اللغة العربية}\\ \end{tabular}

\end{document}

Faheem Mitha

2:46 PM

@DavidPurton I'm thinking that the cable networks here are co-axial, though I'm not sure what that is either.

@DavidCarlisle England is so small and dense, I'm surprised anything counts as rural for the purposes of wired communication.

@DavidCarlisle From what I've read, fiber in India isn't that reliable, either. But, India.

Though in fairness, the lines I currently have here (4 of them) mostly work.

Before that I had MTNL, which was ok for a while, but in recent years had deteriorated alarmingly. And the tech support was basically a joke.

David Carlisle

3:07 PM

@UlrikeFischer tricky, as adding a box squashes any stretch glue so a\dotfill b would be very different. Why is it just luatex, is babel adding the direction controls in the right place?

Ulrike Fischer

3:19 PM

@DavidCarlisle Imho the luatex bidi support is more sophisticated (with xelatex the word order is wrong. I think babel adds the controls with \everyhbox and it somehow gets lossed with colortbl. Is there some grouping involved? Adding \begin{tabular}{c} {\textdir TRT اللغة العربية} \\ \end{tabular} works too, but the braces are necessary.

@DavidCarlisle Oh I mixed up the test cases. Setting the \textdir doesn't work with colortbl either.

We are going to the theater now - Salome will want Johannes' head ...

3

David Carlisle

3:58 PM

@UlrikeFischer oops colortbl inserts the cell content via \unhbox so \everyhbox probably doesn't do what babel is expecting it to do. We should probably come up with a plan with Javier to support this better (I may be able to add some kind of hook at the right place, if that is needed)

Faheem Mitha

6:23 PM

@DavidPurton @DavidCarlisle Are your internet plans unlimited? And if so, is there throttling above a certain point?

Joseph Wright

@FaheemMitha Can't speak for @DavidCarlisle, but I'm on 33Mb download with no monthly transfer limit ...

Faheem Mitha

@JosephWright That's nice. No throttling either? And is the line reliable?

I've got two here, because here they aren't.

Joseph Wright

@FaheemMitha Very reliable (the only issues I've had were I think due to my router); speed is technically capped but realistically the line wouldn't do much better than the speed limit

Faheem Mitha

@JosephWright What is the cap? And does it come into force after a certain amount of data?

Joseph Wright

@FaheemMitha No, speed cap: I only pay for 33Mb/s

Faheem Mitha

6:40 PM

@JosephWright Ok. Because here, if you exceed a certain amount of data, the speed drops dramatically.

Which is annoying, but in practice rarely happens. Recently it's only happened when I had an automated process running which was using a ton of data.

Joseph Wright

@FaheemMitha No: I get that speed all the time, but the technical capability of VDSLv2 is I think 76Mb/s

Faheem Mitha

It was a backup process, but I didn't set it up correctly, and didn't realise how much data it was using.

@JosephWright I see. Well, that's good. Western IPs don't seem to do much data throttling. Probably only if it is really extreme.

Joseph Wright

@FaheemMitha Well 'unlimited' data is of course not really unlimited, but unless one goes mental it should be OK

Faheem Mitha

@JosephWright Right.

David Carlisle

7:11 PM

@FaheemMitha yes no

Faheem Mitha

@DavidCarlisle Ok.

Ulrike Fischer

@DavidCarlisle unhbox seems to be relevant. But I'm not sure what happens, it looks as if babel actively inserts a \begindir TLT when \unhbox is used. But this bidi stuff is rather confusing - luaotfload has code too and it is not always clear who does what.

David Carlisle

@UlrikeFischer raise as a babel issue to get everyone in the loop?

Joseph Wright

@DavidCarlisle All the babel issues

Ulrike Fischer

@DavidCarlisle I could add it. Could you check this. My luaotfload is a dev version and could interfere. Is there a \begindir TLT in the unhbox?

\documentclass[12pt]{book}
\usepackage[bidi=basic,layout=lists]{babel} \babelprovide[import=ar,mapdigits,main]{arabic}
\babelfont{rm}{Amiri}

\begin{document}
\showoutput
اللغة

\setbox0\hbox{اللغة}

\copy 0

\unhbox 0

\end{document}

David Carlisle

7:32 PM

Completed box being shipped out [1]
\vbox(630.3738+0.0)x407.0, direction TRT
.\glue 20.0
.\vbox(610.3738+0.0)x390.0, shifted 17.0, direction TRT
..\vbox(12.0+0.0)x390.0, glue set 5.20898fil, direction TRT
...\glue 0.0 plus 1.0fil
...\hbox(6.79102+1.13672)x390.0, glue set 382.96875fil, direction TRT
....\glue 0.0 plus 1.0fil
....\TU/Amiri(1)/m/n/12 ١
..\glue 19.8738
..\glue(\lineskip) 0.0
..\vbox(548.5+0.0)x390.0, glue set 507.5fil, direction TRT
...\write-{}
...\write1{\babel@aux{arabic}{}}
...\glue(\topskip) 3.36914

@UlrikeFischer ^

@UlrikeFischer presumably the unhbox version here is wrong ^^

Ulrike Fischer

7:58 PM

@DavidCarlisle "presumably"? Someone with your language skills should be sure ;-)

Faheem Mitha

8:38 PM

It seems the default for -shell-escape is restricted, so a reasonable question is - restricted how?

Joseph Wright

@FaheemMitha Only certain commands are allowed

Faheem Mitha

@JosephWright Is there a list available?

Joseph Wright

% The programs listed here are as safe as any we know: they either do
% not write any output files, respect openout_any, or have hard-coded
% restrictions similar to or higher than openout_any=p.  They also have
% no features to invoke arbitrary other programs, and no known
% exploitable bugs.  All to the best of our knowledge.  They also have
% practical use for being called from TeX.
%
shell_escape_commands = \
bibtex,bibtex8,\
extractbb,\
gregorio,\
kpsewhich,\
makeindex,\
repstopdf,\
r-mpost,\

@FaheemMitha ^^^ From texmf.cnf

Faheem Mitha

@JosephWright Oh, thank you. And you can add your own commands?

Joseph Wright

@FaheemMitha Like any texmf.cnf entry

David Carlisle

8:55 PM

@UlrikeFischer I can say with total confidence that one of them is wrong

bp2017

10:00 PM

Do available registers run out when we do \newdimen\someName repeatedly? What happens when \newdimen\someName compiles? I've read that such declaration reserves a (random?) register and makes \someName its alias. I wonder if the register changes when the same declaration is made. I also wonder, if the register does change, is the previous register still available in the list of ready-to-use registers for TeX to choose from or is it out of use permanently for the following \newdimen declarations?

egreg

@bp2017 \newdimen doesn't check whether the following control sequence is already defined and proceeds to allocate a new \dimen register (the next free one). If you do \newdimen\x\newdimen\x, the log file will report

\x=\dimen102
\x=\dimen103

So yes, you can run out of registers. There's no point in redeclaring a register name.

The previous register is essentially wasted.

@bp2017 The numbers listed above depend on many factors; they're not “random”, because the allocation mechanism takes note of the last allocated register number. But different packages loaded can change the assigned number.

bp2017

@egreg, thank you very much. I was looking to define a macro that accepts a name as its parameter. If a dimen with such name exists, it would assign a new value to the existing dimen. If a dimen with such name does not exist, it would create one. The problem is, I don't know yet how to make it work. But the information you provided is helpful in further research.

David Carlisle

10:31 PM

@bp2017 this used to be a big issue because classic tex only has 256 registers of each type but etex (so pdftex and xetex) has 32 thousand and luatex twice that, so in practice you will not run out of register allocations in any normal document

Sebastiano

11:21 PM

@egreg Hi, and good morning. Today is autumn :-)

@egreg Into the site of math.stack I have leaved an answer. If you have a bit of the time, I'm glad of your answer: math.stackexchange.com/questions/3366139/… thank you very much and good night.

egreg

@bp2017 expl3 has \dim_if_exist:NTF

bp2017

11:37 PM

@egreg, @DavidCarlisle, thank you. I wonder if a `def` name can be used instead of a dimen name to store lengths so that to avoid using registers:
\def\pseudoDimen{5.0pt}
\def\pseudoDimen{10.0pt}
\pseudoDimen

What's the point of registers anyway? Why not defs to begin with?

And use \dimexpr to conduct calculations on them.

"What's the point of registers anyway? Why not defs to begin with?"
I meant this for my particular case: to avoid taking up more registers. Defs don't take up registers, do they? (Now I wonder how def contents are stored, oh, well...).

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