\documentclass{article}
\usepackage{xcolor}
\definecolor{fluopink}{rgb}{1.00,0.88,1.00}
\usepackage{listings}
\lstset{language=C,escapechar=\%}
\makeatletter
\newcommand\HL{%
  \gdef\lst@alloverstyle##1{%
    \fboxrule=0pt
    \fboxsep=0pt
    \colorbox{fluopink}{\strut##1}%
  }%
}
\newcommand\HLoff{%
  \xdef\lst@alloverstyle##1{##1}%
}
\makeatother
\begin{document}
\begin{lstlisting}[escapechar=\%,frame=single]
%\HL%int%\HLoff% main(int argc, char **argv){
  printf("Hello world!\n");
  %\HL%return 0;%\HLoff%
}
\end{lstlisting}
\end{document} 