Phantom spaces in listings

Question

I have a problem with SQL code in a PDF document. For code representation I'm using the listings package. Everything works perfect until I copy-paste that code from the created PDF document. I get some phantom spaces in string type. When people are reading my PDF document, they need to copy-paste some of the code. Visually the code looks good in PDF, but when I try to copy-paste my code to NotePad or any other editor I get some unexpected spaces in strings. In the example below, when I copy-paste my SQL code, instead of getting:

SELECT ST_Area(the_geom) 
 FROM katastar 
 WHERE kc_broj = '1414';

I get

SELECT ST_Area(the_geom) 
 FROM katastar 
 WHERE kc_broj = ' 1414 ';

See the spaces in between quotes.

\documentclass{article}
\usepackage{listings,xcolor}

\lstset{
 tabsize=4,
        basicstyle=\scriptsize,
        %upquote=false,
        aboveskip=\baselineskip,
        columns=fixed,
        showstringspaces=false,
        extendedchars=true,
        breaklines=true,
        prebreak = \raisebox{0ex}[0ex][0ex]{\ensuremath{\hookleftarrow}},
 frame=single,
        showtabs=false,
        showspaces=false,
        identifierstyle=\ttfamily,
        keywordstyle=\color[rgb]{0,0,1},
        commentstyle=\color[rgb]{0.133,0.545,0.133},
        stringstyle=\color[rgb]{0.627,0.126,0.941},
 language=SQL
}

\begin{document}
\begin{lstlisting}
SELECT ST_Area(the_geom) 
 FROM katastar 
 WHERE kc_broj = '1414';
\end{lstlisting}
\end{document}

Answer 1

This behaviour is caused by \lstset{columns=fixed}. Changing to columns=flexible or columns=fullflexible should make it go away.

Answer 2

You could always provide the SQL code as "attachments" to the PDF. Of course, that might really only work with Acrobat Reader...

Answer 3

I was looking for a subject about this problem to write what I found out playing around with the fontfamilies.

I used the option columns=fullflexible on my example but it created other problems that was serious to leave them like this. For example I have the following code in a lstlisting environment.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Package: ExampleMyBoxed               %
%                                         %
%   version: 0-1 (beta)                   %
%   Author: Kostis Leledakis              %
%                                         %
%   License: Do anything you want         %
%                                         %
%   Date: 01/Jul/2017                     %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\NeedsTeXFormat{LaTeX2e}[1995/05/16]

the above code with the option columns=fullflexible gives the next result:

But if I remove that option and add the option

basicstyle=\fontfamily{pcr}\selectfont,

then the above problem disappears from the pdf and I can copy paste from the pdf to a text editor. The result in the pdf is:

Of course the above text will not be copied with it's spaces to the text editor... We have to fix it manually... but the rest of the text will not contain extra spaces (it will contain less but may be you can fix it too by combining my answer here with the answer of @PhilippeGoutet here I will make a comment there too because his method with "phantom spaces" doesn't work on my (linux) pdf readers).

Anyway even if you find a solution to add the spaces too even if you don't find and you lose some spaces.. setting :

basicstyle=\fontfamily{pcr}\selectfont

removes the extra spaces without the need of fullflexible columns...

Answer 4

I could fix this problem by setting a different monospace font:

\newfontfamily\listingsfont[Scale=.7]{DejaVu Sans Mono}
\lstset{basicstyle=\listingsfont}

(This is more or less what @Jan Hlavacek describes in his comment)