Avoiding math mode inside a lstlisting

Question

I'm using listings to highlight some PHP code. My problems comes when the code to insert contains the '$' symbol, for example:

\begin{lstlisting}[style=PHP]
Select * FROM users WHERE user_name = $_POST['user'];
\end{lstlisting}

The $ set maths mode and the text after the lstlisting is included until I type another $. I've been looking for solution but unluckily. Using '\$' to escape the symbol $ does not work inside the lstlisting (in my pdf it would appear '\$' and obviously I don't want that to happen).

The PHP lst style is set like follows:

\lstdefinestyle{PHP}{
 frame=tb, to wrap the text with black horizontal lines
 language=php,
 aboveskip=3mm,
 belowskip=3mm,
 showstringspaces=false,
 basicstyle      = \small\ttfamily,
 keywordstyle    = \color{cyan},
 stringstyle     = \color{gray},
 identifierstyle = \color{blue},
 commentstyle    = \color{green},
 emph            =[1]{php},
 emphstyle       =[1]\color{black},
 emph            =[2]{if,and,or,else},
 breaklines=true,
 breakatwhitespace=true,
 tabsize=3,
 %emphstyle       =[2]\color{dkyellow}
}

Answer 1

If you're using TeXnicCenter, and it's only the coloring inside the editor:

This is a listed bug.

The issue also effects the verbatim environment: http://sourceforge.net/p/texniccenter/bugs/318/.

A "not really nice workaround": if it is really annoying (pages of code colored in a wrong way) you can put this after a wrong verbatim or listing environment: \ifx{\verb+$+}!\fi. It can help when you really need the coloring to be right.

Answer 2

Maybe a clearer explanation.

"Text after the dollar sign appears in green" means you are talking about the editor you use for editing the TeX source. This has nothing to do with TeX math mode.

TeX is a completely separate piece of software from the editor. TeX has absolutely no graphical user interface, but a command line interface instead. Editors run TeX in the background the same way you could if you opened a command prompt and typed pdflatex myfile.tex.

The colored stuff you see on the screen is only for your eyes. TeX doesn't care if you edit the source code in Notepad or whatever.