XML listing shows incorrect quotation marks

Question

I'm using \lstinputlisting from listings package to insert an xml file as a listing in my latex file. In the XML file the quotation marks are double quotes as normal when I view my PDF they appear as double closing inverted commas for both the opening and closing. I know that latex requires to use `` and '' for quotation marks but since I'm importing from an XML file, how can I fix this to make them appear normal(so I get proper opening quotation marks)?

Answer 1

In OT1 encoding only a limited set of quotes are available. Try T1 encoding:

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{listings}
\begin{document}

\begin{lstlisting}[language=XML,basicstyle=\fontencoding{OT1}\selectfont]
<root attr1="OT1" attr2='foobar'/>
\end{lstlisting}

\begin{lstlisting}[language=XML]
<root attr1="T1" attr2='foobar'/>
\end{lstlisting}

\end{document}

Or use a typewriter font:

\documentclass{article}
\usepackage{listings}
\begin{document}

\begin{lstlisting}[language=XML,basicstyle=\ttfamily]
<root attr1="foo" attr2='bar'/>
\end{lstlisting}

\end{document}

And I prefer something like

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[variablett]{lmodern}
\usepackage{listings}
\lstset{
  basicstyle=\ttfamily,
  columns=flexible,
}
\begin{document}

\begin{lstlisting}[language=XML]
<root attr1="foo" attr2='bar'/>
\end{lstlisting}

\end{document}

A straight single quote is available in encoding TS1 (package textcomp). In package listings this is enabled by option upquote (Thanks alexis and Paul Gaborit):

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{textcomp}
\usepackage[variablett]{lmodern}
\usepackage{listings}
\lstset{
  basicstyle=\ttfamily,
  columns=flexible,
  upquote,
}
\begin{document}

\begin{lstlisting}[language=XML]
<root attr1="foo" attr2='bar'/>
\end{lstlisting}

\end{document}

Answer 2

Use the listings package option upquote=true to get upright single quotes (requires the textcomp package), together with a tt font style or the T1 encoding to get your double quotes to display as vertical wedges. With the default font and input encoding, your double quotes would all look like double closing quotes.

\documentclass{article}
\usepackage{textcomp}
\lstset{language=XML,upquote=true,basicstyle=\ttfamily}

\begin{document}
\begin{lstlisting}
    <root double="attribute" single='attribute'/>
\end{lstlisting}
\end{document}    

Credit: I learned about the T1 option for getting undirected quotes from @HeikoOberdiek's answer, and I'm including it for completeness. It works like this: basicstyle=\fontencoding{T1}\selectfont (as an alternative to using basicstyle=\ttfamily).