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diff --git a/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-ifpdf.html b/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-ifpdf.html deleted file mode 100644 index 7f26397e5c5..00000000000 --- a/Master/texmf-doc/doc/english/FAQ-en/html/FAQ-ifpdf.html +++ /dev/null @@ -1,80 +0,0 @@ -<head> -<title>UK TeX FAQ -- question label ifpdf</title> -</head><body> -<h3>Am I using PDFTeX?</h3> -<p/>It’s often useful to know whether your macros are operating within -PDFTeX or within (“normal”) TeX; getting the right answer is -surprisingly tricky. -<p/>Suppose you need to test whether your output will be PDF or -DVI. The natural thing is to check whether you have access to -some PDFTeX-only primitive; a good one to try (not least because it -was present in the very first releases of PDFTeX) is -<code>\</code><code>pdfoutput</code>. So you try -<blockquote> -<pre> -\ifx\pdfoutput\undefined - <not running PDFTeX> -\else - <running PDFTeX> -\fi -</pre> -</blockquote><p> -Except that neither branch of this conditional is rock-solid. The -first branch can be misleading, since the “awkward” user could have -written: -<blockquote> -<pre> -\let\pdfoutput\undefined -</pre> -</blockquote><p> -so that your test will falsely choose the first alternative. While -this is a theoretical problem, it is unlikely to be a major one. -<p/>More important is the user who loads a package that uses -LaTeX-style testing for the command name’s existence (for example, -the LaTeX <i>graphics</i> package, which is useful even to the -Plain TeX user). Such a package may have gone ahead of you, so the -test may need to be elaborated: -<blockquote> -<pre> -\ifx\pdfoutput\undefined - <not running PDFTeX> -\else - \ifx\pdfoutput\relax - <not running PDFTeX> - \else - <running PDFTeX> - \fi -\fi -</pre> -</blockquote><p> -If you only want to know whether some PDFTeX extension (such as -marginal kerning) is present, you can stop at this point: you know as -much as you need. -<p/>However, if you need to know whether you’re creating PDF -output, you also need to know about the value of <code>\</code><code>pdfoutput</code>: -<blockquote> -<pre> -\ifx\pdfoutput\undefined - <not running PDFTeX> -\else - \ifx\pdfoutput\relax - <not running PDFTeX> - \else - <running PDFTeX, with...> - \ifnum\pdfoutput>0 - <...PDF output> - \else - <...DVI output> - \fi - \fi -\fi -</pre> -</blockquote><p> -The above is, in essence, what Heiko Oberdiek’s <i>ifpdf</i> -package does; the reasoning is the FAQ’s interpretation of -Heiko’s explanation. -<dl> -<dt><tt><i>ifpdf.sty</i></tt><dd>Distributed with Heiko Oberdiek’s packages <a href="ftp://cam.ctan.org/tex-archive/macros/latex/contrib/oberdiek.zip">macros/latex/contrib/oberdiek</a> (<a href="ftp://cam.ctan.org/tex-archive/macros/latex/contrib/oberdiek.tar.gz">gzipped tar</a>, <a href="http://www.tex.ac.uk/tex-archive/macros/latex/contrib/oberdiek/">browse</a>) -</dl> -<p/><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=ifpdf">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=ifpdf</a> -</body> |