I'm sure this is not an okular bug, because it also happens with pdftotext. pdftotext related to poppler, so it might be a poppler bug.

$ pdftotext /tmp/OkularBug.pdf
$ cat /tmp/OkularBug.txt
Listing 1: Skript um für Eclipse die Projektdateien zu erstellen
#! / b i n / b a s h
sudo apt−g e t i n s t a l l l i b e v d e v −dev l i b g l i b 2 .0− dev
sudo apt−g e t i n s t a l l l i b p c r e 3 l i b p c r e 3 −dev lzma lzma−dev

1

Looks like lstlisting with language=bash recognizes the dashes as short command line option, and tries to do some formatting.

Did you write a bugreport for poppler or should I do that?

No, I didn’t. But the same behavior appears in pdf.js, which is AFAIK not based on poppler. So it must be a bug in listings. Did you try with other arguments for the language option?

I tried with languate=C++ and it is the same.

I think you are right. When I mark the text, I am able to select spaces between characters

By default, the spacing between characters is made uniform so as to preserve alignments (source: https://tex.stackexchange.com/questions/99416/latex-source-code-listing-with-less-space-between-characters)

So this is not a problem of okular or any other library. This is to make the listing clearer to read and the spaces are in the listing it self.

Setting "columns=fullflexible" solves the problem

\documentclass[10pt,a4paper]{article}
\usepackage[latin1]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{listings} % Syntax Highlining, Programmier sprachen
\begin{document}
	\begin{lstlisting}[columns=fullflexible, language=bash,caption={Skript um für Eclipse die Projektdateien zu erstellen}]
	#!/bin/bash
	sudo apt-get install libevdev-dev libglib2.0-dev
	sudo apt-get install libpcre3 libpcre3-dev lzma lzma-dev
	\end{lstlisting}
\end{document}