Generating dummy text programatically using TeX/LaTeX

Question

As part of an attempt to debug another problem, I have a need for a TeX/LaTeX command that generates some dummy text in place. I know of lipsum and blindtext, but they are not what they want. What I have in mind is a command that takes the following arguments: a string (s) and integers (k and n), and produces k occurrences of s per line (no spaces) for n lines. I think this should be possible, even if one has to drop down to TeX to do it. After all, TeX is a text processing Turing complete programming language. Unfortunately, my knowledge of TeX could fit on a postage stamp with space left over, so I'm asking on this forum.

If you have no spaces between s, TeX cannot justify the line because there is nothing stretchable in it. Do you want the text left- or right-aligned? And what to do if the line overfills? — Andrey Vihrov, Aug 08 '11 at 09:23
@Audrey: 1) Ok, lets allow spaces 2) left aligned, though can't one have it do whatever the local default is? I mean, when one normally writes text in a TeX document, one does not need to specify alignment 3) Dunno. let it wrap around? — Faheem Mitha, Aug 08 '11 at 09:45
If by "wrap around" you mean that the text should continue on the next line, then what is the purpose of initially having k occurrences per line? — Andrey Vihrov, Aug 08 '11 at 09:51
@Andrey: Well, the assumption is that the user could reduce k or the length of the string if necessary. To be clear, I mean the text should continue on the next line, and then break. SO you get one complete line of text on line 1, then the overflow text from line 1 on line2, then the second repeated line of text comes on line 3 and so on. — Faheem Mitha, Aug 08 '11 at 09:55

score 11 · Accepted Answer · edited Jul 13 '17 at 08:39

11

The simplest way IMHO to do it is to use \foreach provided by the pgffor package. There is also the lower level \loop\ifnum\j<\k ... \repeat loop which could also be used. However, you need to wrap the inner loop in a group to mask the inner \repeat.

As Andrey already stated there are the open question about how to handle line breaks exactly. I simply use a \\ here, but you might need something else instead, dependent on the exact application. However, the principle usage of the loops is the same.

\documentclass{article}

\usepackage{pgffor}

\newcommand\dummytext[3]{%
    \foreach \n in {1,...,#3} {%
        \foreach \k in {1,...,#2} {%
            #1%
        }%
        \\
    }%
}

\begin{document}


\dummytext{HelloWorld}{5}{10}% 10 lines of 5x 'HelloWorld'

\end{document}

edited Jul 13 '17 at 08:39

David Carlisle

757,742

answered Aug 08 '11 at 09:33

Martin Scharrer

262,582

That works, thanks. However, I think you need #3-1, not #3, and #2-1 not #2. Or starting with 1 will work. In your example you get 11 lines of 6x, not 10 lines of 5x. – Faheem Mitha Aug 08 '11 at 09:51
Yes, indeed. My fault. It should be 1 of course not 0. – Martin Scharrer Aug 08 '11 at 10:10

score 7 · Answer 2 · edited Jul 13 '17 at 08:39

7

And a Plain TeX-style solution using \loop … \repeat:

\documentclass{article}

\makeatletter
\newcommand{\dummy@line}[2]{%
  \begingroup
    \@tempcnta=#2
    \loop\ifnum\@tempcnta>0
      #1\space
      \advance\@tempcnta by -1
    \repeat
  \endgroup}
\newcommand{\dummytext}[3]{%
  \begingroup
    \@tempcnta=#3
    \par\noindent
    \loop\ifnum\@tempcnta>0
      \dummy@line{#1}{#2}\\
      \advance\@tempcnta by -1
    \repeat
    \par
  \endgroup}
\makeatother

\begin{document}

\dummytext{abc}{3}{3}

\end{document}

edited Jul 13 '17 at 08:39

David Carlisle

757,742

answered Aug 08 '11 at 09:48

Andrey Vihrov

22,325

Dumb question, but this function can be used in a LaTeX document even though it is plain TeX, right? – Faheem Mitha Aug 08 '11 at 09:57
@Faheem Mitha: It is a LaTeX document: try compiling it as usual. LaTeX includes much code from Plain TeX. – Andrey Vihrov Aug 08 '11 at 10:00
Yes, so it is. Sorry. I did say it was a dumb question... – Faheem Mitha Aug 08 '11 at 14:06
@Faheem Mitha: You should not apologize for asking questions. Everyone does it in order to learn. – Andrey Vihrov Aug 08 '11 at 14:09

knut · Answer 3 · 2012-01-11T20:53:00.527

You mentioned already blindtext. My first thought was, why not using it? You need only to redefine \blindtext@text to get your string. The other values are optional parameters for \Blindtext.

Unfortunately the missing spaces need also a redefiniton of \blindtext. If you allow spaces (see comments to your question), then just delete the redefiniton of \blindtext.

Below is an example.

\documentclass[11pt, a4paper,english]{article}
\usepackage{babel}
\usepackage{blindtext}
\begin{document}
\makeatletter
%Define text s
\renewcommand\blindtext@text{ab}
\renewcommand\blindtext@parstart{}%since blindtext version 2.0
%remove spaces
\renewcommand{\blindtext}[1][\value{blindtext}]{%
  \blind@checklanguage
  \blind@countxx=1 %
  \loop
    \blindtext@text%    here was a \
  \ifnum\blind@countxx<#1\advance\blind@countxx by 1 %
  \repeat
}
\makeatother

%5 lines
%7repetions
\Blindtext[5][7]

\end{document}

score 2 · Answer 4 · answered Jan 11 '12 at 21:35

Using LaTeX3 it's almost a one liner; the \dummy_endline: macro makes sure that a paragraph is terminated after each line; of course, if the copies of the string fill more than a line, they will be wrapped. If you don't care about Underfull \hbox messages, put \linebreak in place of \dummy_endline:.

\documentclass{article}
\usepackage{xparse}
\ExplSyntaxOn
\NewDocumentCommand{\dummy}{m m m}
  {
   \prg_replicate:nn { #3 }
     {
      \prg_replicate:nn { #2 } { #1 \hfill } \dummy_endline:
     }
 }
\cs_new:Npn \dummy_endline: 
  { { \parfillskip=0pt\par } }

\ExplSyntaxOff

\begin{document}

\setlength{\parindent}{0pt}

\dummy{HelloWorld!}{5}{10}

\end{document}

Still using TeX Live 2009, which doesn't seem to have xparse. Yes, I know 2009 is antediluvian. — Faheem Mitha, Jan 12 '12 at 05:45

Generating dummy text programatically using TeX/LaTeX

4 Answers4

Linked