Listings with color OR tilde, not both

Question

Trying to get a listing block with a command prompt that has both color and a proper formatting. I can get the proper format with a simple black typeset, but not with color...the tilde (signifying home directory) is omitted.

Example:

\documentclass{article}
\usepackage{listings}
\usepackage{lmodern}
\usepackage[dvipsnames]{xcolor} 

\lstset{
    showstringspaces=false,
    basicstyle=\ttfamily,
    columns=flexible,
    escapeinside={(*}{*)}
    }

\begin{document}
%first prompt is colored but missing the tilde
%second prompt is b/w, but the tilde shows
%   - but the tilde is in the wrong position...
\begin{lstlisting}[caption={Command prompt}]
(*\color{red}root*)(*\color{ForestGreen}@hostname:~\#*)
root@hostname:~# 
\end{lstlisting}

\end{document}

Answer 1

I recommend to not use escapeinside for this purpose, as it somewhat defeats the purpose to leave the verbatim environment and use special commands to still get them typeset verbatim. Instead use the features listings provides for styling your code. Here are two suggestions to get the desired result.

Define keywords

listings allows you to define several sets of keywords where each set can be styled differently. So we can just define set 1 to consist of only the root keyword and apply the red color to this keyword. Green then becomes the default color for your listing. Note that @ has to be redefined as other character to allow listings' keyword parser to properly stop whenever an @ occurs in the input.

\lstset{
    basicstyle   = {\ttfamily\color{ForestGreen}},
    keywords     = [1]{root},
    keywordstyle = [1]{\color{red}},
    alsoother    = {@}
}

Use the literate option

Keywords work quite well in many cases, but sometimes we need to consider a bit more context. In case you only want root to be displayed red when it occurs before an @, you can define a literate rule to replace each literal occurence of root@ by a properly styled replacement text, in that case a red root string and an @ that has the default style.

\lstset{
    basicstyle = {\ttfamily\color{ForestGreen}},
    literate   = {root@}{{\color{red}root}@}5
}

---

EDIT: More pleasant tilde

As noted in one of the comments, the default tilde character is too high for the use in filepaths. The url package provides a more pleasant version that can be used throughout our listings by also using the literate option as mentioned above. We just add the following line to \lstset:

literate={~}{\urltilde}1

where \urltilde is defined as

\newcommand\urltilde{\url{~}}

---

Here's the (updated) full code for both versions:

\documentclass{article}
\usepackage{listings}
\usepackage{lmodern}
\usepackage[dvipsnames]{xcolor} 
\usepackage{url} 

\newcommand\urltilde{\url{~}}

\begin{document}

\lstset{
    showstringspaces=false,
    columns=flexible,
    escapeinside={(*}{*)},
    basicstyle={\ttfamily\color{ForestGreen}},
    keywords=[1]{root},
    keywordstyle=[1]{\color{red}},
    alsoother={@},
    literate={~}{\urltilde}1
}
\begin{lstlisting}[caption={Command prompt}]
(*\color{red}root*)(*\color{ForestGreen}@hostname:~\#*)
root@hostname:~#
\end{lstlisting}

\bigskip

\lstset{
    showstringspaces=false,
    columns=flexible,
    escapeinside={(*}{*)},
    basicstyle={\ttfamily\color{ForestGreen}},
    literate={root@}{{\color{red}root}@}5 {~}{\urltilde}1
}
\begin{lstlisting}[caption={Command prompt}]
(*\color{red}root*)(*\color{ForestGreen}@hostname:~\#*)
root@hostname:~#
\end{lstlisting}

\end{document}

Answer 2

Try using \textasciitilde in place of the tilde symbol:

(*\color{red}root*)(*\color{ForestGreen}@hostname:\textasciitilde\#*)