Latex: access the content of an environment while using \newenvironment

I'm trying to make my own environment with \newenvironment.

Is it somehow possible to access the "body" of the environment?

For example if the user uses

\begin{myenv}
    i'm the content
\end{myenv}

i want to analyze the "i'm the content" in the definition of the environment.

Thanks in advance,

Jan开发者_如何学JAVA Oliver Oelerich

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Use package 'environ'.

\NewEnviron{myenv}{\colorbox[gray]{0.7}{\BODY}} 

where \BODY is a your "body".