{catcodes} is about "category codes" — an integer number from 0–15 associated to each of the 256 character codes. The category codes indicate the role of a character.

learn more… | top users | synonyms

2
votes
1answer
590 views

Scope of catcode change for escape character ?

In the following macro, I change the category code for the escape character (\) to "other" (12): \def\xxA{\begingroup \catcode`\\ = 12 \gdef\xxB ##1z{\tt ##1\endgroup} \xxB} How the heck does ...
13
votes
1answer
424 views

Is there a \show for catcodes?

In the course of attempting to out-pedant another mathematician, I wanted to \show the catcode of $ to convince myself that it was a "special" character in ordinary TeX as well as LaTeX. I was just ...
14
votes
2answers
395 views

Macro to take a character as argument, make it active, then \def it.

I have a XeLaTeX document in which I want some unicode symbols to be auto-substituted, like ¼ → 1/4, » → >>, « → <<. But instead of a long list like \catcode`\¼=\active\def¼{1/4} \catcode`\«=\...
5
votes
2answers
197 views

Changing catcode for commercial at (@) inside a macro to get it matched in pattern.

This question is related to TikZ: pgfutil-common: pgfutil@in@ - how does it work? and is a result of coping with that problem. I've already read How to change #catcode in a macro, but it didn't help ...
45
votes
4answers
3k views

What are category codes?

Following on from this question, I'd like to ask a more general question: What are category codes, and what can I achieve by changing them?
6
votes
1answer
1k views

Using tilde `~` in csname in Beamer

In beamer, I would like to be able to use the tilde character ~ in the name of a command sequence. I tried with adjusting catcodes. While this was successful with the standard article class, it failed ...
15
votes
1answer
890 views

How to change the catcode in a macro

I want to change the catcode in a macro, but it seems it doesn't work. Can anyone help me? \def\A{\catcode`\|=0 |bf{test}} |bf{test} would not work as expect.
22
votes
2answers
883 views

How bad is slack \makeatother discipline really?

Following Will Robertson's admission that Fwiw, i'm not aware of any troubles with a missing \makeatother, but you're right. It's a bad habit of mine to omit it, and my own progressive slackness about ...
2
votes
2answers
670 views

ignorespace and unskip in verbatim/listings?

I am writing a \bashDemo macro that will (a) execute its argument in a shell, e.g., bash, script, and (b) display the argument in a listings. So, \bashDemo ls -ls > myfiles \END will both run ls ...
4
votes
2answers
152 views

Command to display free-text answers from a survey, eliminating ascii control chars

I'd like to create a report from a survey with free-text answers that is collected in a database. For each question there are typically many answers which I could present in an itemize environment, ...
4
votes
2answers
211 views

Get tokens between two commands

I'm trying to create a screenplay-like class that uses a very simple syntax to create the dialogue, and dumps it as a plain text file for use in subtitles. To divide the subtitle sections I use &, ...
415
votes
1answer
67k views

What do \makeatletter and \makeatother do?

Many LaTeX “hacks” begin with \makeatletter and end with \makeatother. What do these commands do?
10
votes
4answers
757 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 ...
20
votes
4answers
3k views

How to make a real backslash (escape) character?

I just want a good way to make a backslash character (or whatever character(s) any given format uses as escape characters), suitable to \write to a file or pass to a pdfTeX primitive. Let me ...
45
votes
1answer
4k views

Is it \catcode or \catcode`?

I've noticed that \catcode is poorly documented in the TeXbook. The primitive is defined as \catcode but every time it is used, it is used as \catcode` ... the backquote is never discussed. ` itself ...
4
votes
2answers
568 views

How to test whether next token on input stream is catcode 10

Why doesn't the following code work? From a failed, now fixed, SO answer of mine: \documentclass{article} \usepackage{expl3} \ExplSyntaxOn \newcommand\latinabbrev[1]{ \peek_meaning:NTF . {% Same ...