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Diffstat (limited to 'Master/texmf-dist/tex/latex/randtext')
| -rw-r--r-- | Master/texmf-dist/tex/latex/randtext/randtext.sty | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/Master/texmf-dist/tex/latex/randtext/randtext.sty b/Master/texmf-dist/tex/latex/randtext/randtext.sty new file mode 100644 index 00000000000..0274642c878 --- /dev/null +++ b/Master/texmf-dist/tex/latex/randtext/randtext.sty @@ -0,0 +1,143 @@ +% +% randtext.sty +% +% Charles Duan (2004/12/20) +% +% Provides one useful macro, \randomize{TEXT}. Result is a typeset box that +% looks, on paper, like TEXT, but whose letters have in fact been placed in +% random order so that they are not copiable from the file directly. +% +% In other words, typing: +% +% This is a \randomize{random-text} test. +% +% would produce output that looks like: +% +% This is a random-text test. +% +% but if you tried to copy-paste it from the output file, you would probably get +% +% This is a mdoxt-etnra test. +% +% The function of this odd macro is to obfuscate e-mail addresses, say on a PDF +% document put online, so that the human reader sees the address as expected, +% but e-mail address harvesters and spambots cannot determine the address. Since +% this macro is done entirely using TeX typesetting commands, it requires no +% external image generation or anything, and the typeset result is just as +% high-quality as if no obfuscation had taken place. +% +% This macro does take into account kerning between character pairs, but it does +% not account for ligatures. To make appropriate ligatures, surround the +% ligature characters with braces. +% +% This package supersedes "switcheml.sty", written by the same author. (That is +% the reason that the internal macros begin with "se@". +% +% Requires the file "random.tex", by Donald Arseneau. I believe that this file +% comes as part of a standard TeX distribution. +% +% +\ProvidesPackage{randtext}[2004/12/20 Obfuscate text] +% +% We use the random package to pick random numbers. +\input random +% +% \se@count stores the number of letters/groups to typeset. For instance, +% \randomize{abc{de}fg{hij}kl} +% contains 9 letters/groups. +\newcount\se@count +% +% \se@random is a random number register. +\newcount\se@random +% +% \se@pos is used to store the width of each section of the randomized text. +\newdimen\se@pos +% +% Randomize the text of the argument. +\def\randomize#1{% + % Do nothing for empty argument. + \def\se@tmp{#1}\ifx\se@tmp\@empty\else + % Make our work local + \begingroup + % In case this is the first thing in the paragraph, go to horizontal + % mode + \leavevmode + % Initialize \se@count=1, \se@pos=0pt + \se@count\@ne + \se@pos\z@ + % Now iterate over the argument text. The \relax is put at the end + % as an untypeset token. + \se@randomize#1\relax\@stop + \endgroup + \fi +} +% +% Iterator function for \randomize. Essentially, this function will be executed +% once for each token in the list. +\def\se@randomize#1#2#3\@stop{% + % Define a macro \pos@[\se@count]. Essentially, this makes a unique, + % numbered macro for each letter/group. + \expandafter\edef\csname pos@\the\se@count\endcsname{% + % The macro produces a zero-width box that jumps forward \se@pos and + % then typesets the letter/group. Note the \the\se@pos, to force current + % evaluation of the distance to move forward. + \noexpand\rlap{\hskip\the\se@pos\relax#1}% + }% + % Advance \se@pos forward by the width of the first group and the + % immediately subsequent group, and then backward by the width of the second + % group. The effect is to advance \se@pos by the first group and the kern + % between the first and second groups. + \setbox\z@\hbox{#1#2}\advance\se@pos\wd\z@ + \setbox\z@\hbox{#2}\advance\se@pos-\wd\z@ + % + % If there's nothing left to iterate over, then: + % \se@pos is the width of the whole text + % \se@count is the number of letters/groups, or the highest \pos@[number] + % so we make a box of width \se@pos, place our random letters in it with + % \se@rand@place, and fill up the box for good measure. + % + % Otherwise, increment \se@count and run the function again. + % + % Note two things: + % 1. We put braces around #2 but not #3. Since there's an extra \relax at + % the end of #3 at all times, we don't have the problem of TeX stripping any + % braces from it. + % 2. The other reason we needed that \relax was that, since we read + % letters/groups in pairs, the last letter/group would only be read if there + % was an extra token at the end (i.e., the \relax). + \def\se@tmp{#3}\ifx\se@tmp\@empty \expandafter\@firstoftwo + \else \expandafter\@secondoftwo \fi + {\hb@xt@\se@pos{\se@rand@place\hfill}}% + {\advance\se@count\@ne\se@randomize{#2}#3\@stop}% +} +% +% Now all of our \pos@[number] functions are set, and we just need to randomly +% select and place. +\def\se@rand@place{% + % + % Pick a random number between one and \se@num. (If \se@num>3, then ensure + % that the number is over three. This way, the first two elements will + % always be typeset last, guaranteeing at least some contortion.) + \ifnum\se@count>\z@ + \ifnum\se@count>\thr@@ + \setrannum\se@random\thr@@\se@count + \else + \setrannum\se@random\@ne\se@count + \fi + % Execute \pos@[\se@random]. + \csname pos@\the\se@random\endcsname + % Now replace \pos@[\se@random] with \pos@[\se@count] and decrement + % \se@count. This way, the next random number will be guaranteed to + % typeset an unselected value. + \ifnum\se@random=\se@count\else + \edef\reserved@a{% + \let\expandafter\noexpand\csname pos@\the\se@random\endcsname + \expandafter\noexpand\csname pos@\the\se@count\endcsname + }\reserved@a + \fi + \advance\se@count\m@ne + % Repeat + \expandafter\se@rand@place + \fi +} +\endinput |