[Tex/LaTex] lstinputlisting does not include file within lstnewenvironment

Question

I want to use lstinputlisting to include a file with code within an lstlisting block, which is defined through a new environment. However, the lstinputlisting command itself, not the code, is reproduced verbatim in the code block. MWE:

\documentclass{minimal}
\usepackage{color}
\usepackage{listings}
\usepackage{verbatim}

\definecolor{customblue}{RGB}{235,241,245}

\lstnewenvironment{terminalblock}{%
  \lstset{backgroundcolor=\color{customblue},
  frame=single,
  framerule=0pt,
  basicstyle=\ttfamily,
  breaklines=true,
  columns=fullflexible}}{}

\begin{document}
 \begin{terminalblock}
  \lstinputlisting{code.cpp}
 \end{terminalblock}

\begin{verbatim}
 \verbatiminput{code.cpp}
\end{verbatim}

\begin{lstlisting}
 \lstinputlisting{code.cpp}
\end{lstlisting}

\end{document}

The same problem occurs in the standard lstlisting and verbatim environments as well. The PDF document just contains \lstinputlisting{code.cpp} three times, as shown.

Since the background of the block generated by the custom environment is the correct colour, so I think the configuration settings are working in the custom environment, but not lstinputlistings. I don't know if it's relevant, but these are the contents of code.cpp:

#include <iostream>
#define abusing using

abusing namespace std;

int main()
{
   cout<<"Hello, world!"<<endl;
   return 0;
}

Answer 1

The terminalblock environmnet is for code directly input; it doesn't make much sense to use \lstinputlistings inside this environment since it will be taken verbatim (although it could be done, for example, by escaping to LaTeX). A better approach is to define a style and use this style both for your environment (to be used to input direct code) and for \lstinputlistings (to be used to include code from external files); also notice that you are using frame=single, but setting the rule width to 0pt so no lines will be drawn.

Here's your code with the defined style and \lstinputlisting:

\documentclass{article}
\usepackage{color}
\usepackage{listings}

\definecolor{customblue}{RGB}{235,241,245}

\lstdefinestyle{mystyle}{%
  backgroundcolor=\color{customblue},
  frame=single,
  framerule=0pt,
  basicstyle=\ttfamily,
  breaklines=true,
  columns=fullflexible
}

\lstnewenvironment{terminalblock}{%
  \lstset{style=mystyle}}{}

\begin{document}
\lstinputlisting[style=mystyle]{code.cpp}
\end{document}

and with the terminalblock environment:

\documentclass{minimal}
\usepackage{color}
\usepackage{listings}

\definecolor{customblue}{RGB}{235,241,245}

\lstdefinestyle{mystyle}{%
  backgroundcolor=\color{customblue},
  frame=single,
  framerule=0pt,
  basicstyle=\ttfamily,
  breaklines=true,
  columns=fullflexible
}

\lstnewenvironment{terminalblock}{%
  \lstset{style=mystyle}}{}

\begin{document}

\begin{terminalblock}
#include <iostream>
#define abusing using

abusing namespace std;

int main()
{
   cout<<"Hello, world!"<<endl;
   return 0;
}
\end{terminalblock}

\end{document}