What are good ways to make pdflatex output copy-and-pasteable?

Question

One frequent aspect of pdflatex output that could be improved is to what extent one can select text output from the generated pdf-file and copy-and-paste it. This is essentially an issue of having the right output encoding. There are at least two important aspects to this:

• In the ideal case, Unicode would be the output encoding.
• Ligature glyphs (such as fi) are ideally de-ligated in the output (here: "fi").

It seems that output encodings are specified through the fontenc package. What is the range of possible output encodings, and most importantly: Is there a way to specify a Unicode output encoding and one that deals with ligatures in the intended way?

(Note: It is important to distinguish output from input encodings. How to use different input encodings in LaTeX has been documented widely. My understanding is that this is best handled by the inputenx package, as it supersedes the inputenc package.)

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Quick guide to the solutions: The information in the answers and answer threads is a bit distributed, so here the short summary: one approach is to use \input glyphtounicode together with \pdfgentounicode=1; the other approach is to use cmap/mmap.

Answer 1

Do you Know the package cmap (look at CTAN:cmap)? It does this for you. Load it with \usepackage{cmap} as first package.

Update: I did a little research and found some hints how to use cmap or mmap. Result: cmap and mmap can't handle fonts based on virtual fonts (files *.vf or *.vpl in the font directory). So if your used font needs virtual fonts cmap or mmap can't work. You should better use glyphtounicode. This hint could be useful.

BTW: cmap is based on the character maps of Adobe. See PDF reference Version 1.6 for more information.

Update2: With texdoc encguide you will get a document describing the T1 Cork encoding. There you will find a table showing all the glyphs you can directly write in your pdf file. Because there is a glyph ä you can find ä in your pdf file. If there is no glyph ä LaTeX has to build it with two characters: "a. You will see ä in your pdf file but you can't find it (to search "a could help; copy and paste give you this back).

Update 3: glyphtounicode supports only the T1-encoding, cmap supports many more encodings. One advantage of glyphtounicode is that one can add with one command more glyphs which haven't yet been included in the official list. More information about \glyphtounicode is here: tb91thanh-fonts.pdf. Make sure to get the latest version of glyphtounicode.tex from LCDF Type Software and see this caveat on how to properly use it.

Answer 2

As you don't provide a minimal example, I am not sure if this really addresses your problem. Have you tried loading glyphtounicode.tex?

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\input glyphtounicode
\pdfgentounicode=1

\begin{document}

ff ffi ffl ä ü ö ß

auffallen

\end{document}

However, even without using glyphtounicode, pdftotext produces unicode text on my system. With glyphtounicode, the ligatures get de-ligated.

Answer 3

If you are using memoir, you can compile your document with the option ms. The output is like something that are written with a typewriter, but since it has no hyphenation, it is easy to copy and paste the text for reuse in another program, such as Word or LibreOffice Writer.

I often use this option as a quick and dirty way to get the text in a LaTeX document into Word.

Since memoir use 1.5 line spacing in ms-mode, it is important to set the number of lines per pages to a number that is not overfilling the page.

A MWE:

\documentclass{ms,article}{memoir}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lipsum}

\input{glyphtounicode}
\pdfgentounicode=1

\setulmargins{*}{*}{1,5}
\setlength{\textheight}{32\baselineskip}
\checkandfixthelayout[lines]


\begin{document}

\lipsum[1-21]

\end{document}

EDIT: user14996 asked: Why glyphtounicode doesn't make a difference in output or pasting behavior when the fontenc-line is used?

The answer to that is: It depends on your font. I use MinionPro, which use minuscule figures (oldstylenums) as standard. I also use spaced small capitals. With the glyphtounicode, but without the fontenc, loaded, Norwegian characters (æøå ÆØÅ) is not copied correctly from the PDF-file. On the other hand, all numbers and small caps can be copied and pasted. If I do the opposite, remove glyptounicode but keep fontenc, the numbers comes out as Greek characters, and the small caps disappear. Also, all ligatures (fi ffi fj) disappear.

Using cmap in stead of glyphtounicode does not help.

So the answer is that sometimes fontenc is the only package you need, but if you use special features in a font (small caps, old style figures etc.) which require virtual fonts, you need to load glyphtounicode. cmap does not support virtual fonts. Sometimes not even glyphtounicode solves all problems.

Answer 4

I had this problem for quite some time in the past. I solved it in a way which worked well for me, and I found the following notes about it:

\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}

I agree that fontenc (as encoding of the output) is what you would expect. However, I have been using the german package as well. And that tends to assemle german umlauts as strange custom tokens (like an 'a' with two dots drawn on top of it rather than the correct unicode char). I used inputenc to fix that.

I understand that this answer addresses mainly the question "How can I make pdflatex output copy-pastable pdfs?". It leaves the predicate "good" for others who might be able to answer your specific questions. But perhaps this is still useful as it seemed to work fine, or at least fine enough.