{tex-core} is for questions that are independent of formats and macro packages. Such questions usually relate to low-level TeX programming or the behaviour of TeX at an underlying level. Note that even Plain TeX is a format in itself; for questions about it, use {plain-tex}.
10
votes
2answers
171 views
What does \relax do? [duplicate]
Possible Duplicate:
How can I speed up LaTeX compilation?
What is the difference between \relax and {}?
The title suggest the question. On and off, I see macros here in TeX.SE and I see ...
10
votes
1answer
117 views
How to install or replace fonts in old TeX files?
I got interested in a research paper from 1991, which I cannot get an electronic online version of. The author was kind enough to send me his tex sources, but is himself unable to produce a pdf file ...
10
votes
3answers
1k views
How to use \valign?
I just bumped into a interesting command called \valign. It seems to be the sister of \halign, but the TeXbook seems to be rather shy on explaining its use. As is the TeX by Topic. They only mention ...
10
votes
1answer
574 views
Simple un-obfuscation of some LaTeX internals
Here's an example of some code from LaTeX's \DeclareFontFamily:
\def\reserved@a{#3}
\global
\expandafter\let\csname #1+#2\expandafter\endcsname
\ifx \reserved@a\@empty
\@empty
...
10
votes
1answer
106 views
How many different concepts of “token equivalence” are there in TeX?
I was living in the delusion that the "token equality" tested by \ifx was the only thing you need to remember about this subject, but this week I learned otherwise (thanks to David Carlisle).
Now ...
10
votes
2answers
280 views
Starting point for getting more familiar with TeX/LaTex etc
Background: I've been using what I would call LaTex for ~4 yrs to typeset assignments, reports, essays and tutorial notes. I have been using "TexShop" (for Macs) - mostly because it was simple when I ...
9
votes
3answers
145 views
Check for empty macro argument
There is a description on how to check whether the argument of a macro is empty in What does \ifx\\#1\\ stand for?
Unfortunately, I can't get any of the examples there to work.
Among others, I have ...
9
votes
3answers
375 views
Does the \relax side-effect of \csname…\endcsname still have a use?
I find it annoying that using \csname...\endcsname will define ... to be \relax if ... is undefined, and there is no improved primitive that does not have this side-effect, though there are partial ...
9
votes
2answers
796 views
Which “TeX” should one use?
This question is from my confusion with the editor. In the WinEdt 6.0, there is a button for different kinds of "TeX". How do I know which one I should use and what's the difference?
9
votes
4answers
186 views
Dividing dimensions to get a count
Is there a way to divide two dimens and get a count? For example, if I have a box that doesn't fit on a single page, and I want to know the number of pages I'd need for the box (i.e., \heightofbox / ...
9
votes
2answers
405 views
How to get the catcode of a token?
For debugging a complicated macro I would like to print out the catcode of a token. Optimally I would like to have a macro \getcatcode such that, for example, \getcatcode{a} would expand to 10. How ...
9
votes
2answers
472 views
What is the plain TeX equivalent of \settowidth?
The \settowidth command, which sets a width equal to the width of some text, is described at Get width of a given text as length and How to set the width of the label of a description to the width of ...
9
votes
1answer
123 views
Can TeX detect a newline at the end of the file?
Is TeX able to distinguish beween a file containing, say, the single character a/ byte 97; and a file containing this same character followed by a newline marker (which is system-dependent)?
I had a ...
9
votes
2answers
678 views
How to avoid underfull vbox in combination with \vsplit?
In the following example I am using the command \vsplit. I can't see the reason why \vsplit produced an overfull \vbox
\documentclass{article}
\parindent0pt
\def\exampletext{Text Text Text Text Text ...
9
votes
2answers
135 views
Local allocation of registers
I saw the following code in an issue of TUGboat (Volume 9, 1988, No. 3). I have modified it slightly. The motive was to avoid allocating registers globally. My questions are (1) How safe is it for ...
9
votes
2answers
126 views
How can the contents of a TeX \mark be viewed?
The purpose of marks in TeX is to generate running heads. One inserts material to a mark, simply by:
\mark{A running head}
If we write a short TeX program, we can see that the contents of \mark ...
9
votes
5answers
448 views
Test if token is a control sequence
Sometimes more complex (La)TeX macros test the next input token and branch dependent on its type. I'm aware how to test for catcodes and character codes, but sometimes I like to handle control ...
9
votes
3answers
318 views
Verbatim text in token registers
How can I add verbatim text in a token register (I want to accumulate pieces of code in a toks register and print them in an appendix). In the MWE below if you substitute verbatim text it fails.
...
9
votes
2answers
101 views
How can I specify text to be included in the pdflatex output log during compilation.
I would like to be able to have some kind of logging command that is able to log text to the default pdflatex logfile (<input-base-filename>.log). Is this possible, and if so, how?
In ...
9
votes
4answers
894 views
Generalize \@ifnextchar to consider more than one character.
I am looking for a clever way to write a switch statement based on the next input characters, ideally, one could write:
\@switchnextchars
\@case{abc}{\typeout{You gave me an abc}}%
...
9
votes
2answers
172 views
Missing baselineskips?
Here are some cases where when there is stuff inside a vbox, the baselineskips are sometimes there and sometimes not. Or maybe it's something else that is producing the differences?
\setbox0\vbox{% ...
9
votes
1answer
262 views
Computer Modern font with accented characters (in XeTeX)
I'd like to use Knuth's Computer Modern font with XeTeX (not with XeLaTeX and so not with a LaTeX package) in a way where I don't have to type accents in a \'-way and without any gimmick such as ...
9
votes
2answers
211 views
How to use tex -ini, tex -fmt, initex and fmtutil?
What are the roles of each of these commands?
What is the good command to create a new format ?
9
votes
2answers
256 views
Difference between unrestricted and internal vertical mode
At any point in the processing of a document, TeX can be in one of seven modes: no mode (only in \write and similar commands, I think), math mode ($...$), display math mode ($$...$$), restricted ...
9
votes
1answer
510 views
Why \leaders and \mkern works strangely in different font size?
I can hardly determine a good title for this question, I'm sorry.
Minimal test code:
\documentclass{minimal}
\usepackage{lipsum}
\begin{document}
foo
{\fontsize{18}{18}\leaders\hbox{$\mkern ...
9
votes
1answer
169 views
Macro delimiter
I'd like to have a macro to split up another macro content, with field separator being a space. So:
\def\mytext{foo bar}
\def\secondof#1 #2{#2}
\secondof\mytext
What? What do you mean: "runaway ...
9
votes
1answer
120 views
Emulate TeX's grouping
In TeX, various kinds of groups must match properly, for instance, the following is wrong:
$ \begingroup $ \endgroup
I would like macros which allow such mismatched grouping. They would keep ...
9
votes
2answers
332 views
New lines and TeX: difference between ^^J and ^^M
What is a new line for TeX in the following contexts:
When reading from a file.
When writing to a file.
After having read a % character.
In a \scantokens.
I am asking in particular because the ...
9
votes
4answers
465 views
How do I get the category code of a character that is the value of a control sequence?
How can I get the category code of a character that is the value of a control sequence?
If I do this
The catcode for A is \the\catcode`A.
I get
The catcode for A is 11.
If I do this
\let\abc=A
...
9
votes
1answer
223 views
What documentation thoroughly explains how to use TeX conditionals?
I have a document which needs a large variety of plain TeX conditionals, e.g.:
IF #1 >= 1 AND #2 >= 10
IF #1 != “tree” OR #2 == “mountain”
IF 10 > #1 > 2
I have found limited ...
9
votes
1answer
815 views
Newline/linebreak in \message
I want to prompt some messages to my console. I used
\message{Hi out there!}
Now i want some more Text but with an linebreak.
\message{Hello World %some line break here
Salut monde
}
Well i ...
9
votes
1answer
629 views
Expansion in \numexpr…\relax versus \pdfstrcmp
The \numexpr...\relax construction in eTeX allows to evaluate numerical expressions, and it expands tokens fully as it goes.
The \pdfstrcmp{...}{...} construction in pdfTeX lets us compare two lists ...
9
votes
2answers
505 views
Do XeTeX and LuaTeX always use Unicode?
I am writing some functions to manipulate strings. A typical way to produce a character with a given character code is the \lowercase primitive. The following code produces a character with code 234, ...
9
votes
1answer
208 views
Making a range macro
Having syntactic sugar for ranges can be useful in programming languages. For example in Ruby, one can use a range by
(2..10).map {|elem| elem + 1}
to get an array consisting of each element in the ...
9
votes
1answer
216 views
How can I make a PDF of the source of pdftex?
I got the files tex.web and pdftex.web from the texlive svn repo. I ran
weave tex.web
pdftex tex.tex
which produced a file tex.pdf with a nicely typeset, cross-referenced listing of the WEB source ...
9
votes
2answers
182 views
Hooks into mathmode
Short version
Is there a way to pipe every symbol in a math environment unevaluated to an external program w/o manipulating the (La)TeX file directly (except for adding header files) or patching TeX ...
9
votes
1answer
113 views
Why does the list of recent contributions contain exactly two boxes?
In the transcript of
\nonstopmode
\tenrm
\vsize=2cm
\output={\shipout\vbox{
\showlists
\unvbox255
}}
\hbox{blah}
\hbox{blah}
\hbox{blah}
\hbox{blah}
\hbox{blah}
\hbox{blah}
\hbox{blah}
...
8
votes
4answers
247 views
Does macros get applied to the source code before compilation?
I wonder if this is true.
The latex compiler first run though the document, and search for all the macro declarations.
the compiler then go though the document, apply each macro as a string ...
8
votes
2answers
189 views
What is wrong with this TeX macro
Still soldiering on with trying to learn these macros. Can someone tell me why this isn't working?
The macro \mycline{n-n} is supposed to expand to \cmidrule{1-1} ... \cmidrule{n-n}, but in my code ...
8
votes
2answers
138 views
Where to find official (!) and extended documentation for tex/latex's commandline options (especially -interaction modes)?
Today I tried to learn more about the several interaction modes for tex/latex/pdflatex etc. The manpages turned out to be not very helpful:
$ man tex
...
-interaction mode
Sets the ...
8
votes
2answers
490 views
Selecting optical size?
For some time I've seen LaTeX-produced documents that had slight differences in fonts. When you looked at them, they had the same Computer-Modern or Latin-Modern, however, they looked more stylized ...
8
votes
3answers
907 views
How to make a ruler
In The TeXbook (Ch. 10, after exercise 10.3), DEK shows some nice rulers. But I couldn't figure out how he did them. I'm sure I could look it up from the texbook source, but for some reason I'm ...
8
votes
3answers
317 views
How to make a plain TeX conditional which checks if some specific numbers are present?
I need to make a simple conditional in a macro. If #1 is "1", "2", "3", "4", "5", or "6", then print Text: #1, otherwise, do nothing, even if it is empty. I tried this code:
\ifnum#1=1
Text:~#1
...
8
votes
1answer
649 views
Breakable vboxes
In Plain TeX how can I make vboxes breakable, and can I handle/measure them separately? What I'm trying to do, is that I have a portion of text, that is treated separately (no indention, narrower, ...
8
votes
2answers
284 views
Checking whether a file is empty?
Well, the obvious way to do that is with \ifeof, but for some reason, I cannot do this right. I wrote
\newread\reader
\openin\reader=empty \relax
\ifeof\reader\message{empty}\else\message{not ...
8
votes
1answer
121 views
Which commands exist to define new commands?
Which commands are there that one can use to define new commands in (La)TeX?
There are: \let, \def, \[re]newcommand[*], \DeclareRobustCommand[*], and ...?
(And I've seen things like ...
8
votes
3answers
115 views
Questions on macro writing in TeX to modify an existing style file: fancybox.sty
I've decided that I must become more adept at TeX if I'm to become proficient with LaTeX. While this is probably obvious to most readers who pass by, my ability to muddle through has hidden this small ...
8
votes
2answers
110 views
Is it possible to remove (or otherwise nullify) a whatsit node from a box?
I am aware that it is not generally possible to modify the contents of a box (as per http://tex.stackexchange.com/a/49903/17427), though I believe it is sometimes possible to "unbox" material and hack ...
8
votes
2answers
220 views
Normal \relax vs. frozen \relax
With
\edef\x{\ifnum0=0\else\fi}
being \relax and with
\def\y{\relax}
we see that \ifx\x\y is false. Why?
See also \ifcsname when it isn't apparent that the command is \relax'ed.
8
votes
3answers
656 views
`\write` non-printable ASCII characters to a file
\immediate\write\SomeStream{x} writes x to the file open in \SomeStream. I would like to write non-printable ASCII characters, such as ``, to a file. My naive guess is
\begingroup %To keep ...
