We recently turned off the websites' ability to use the eval() or related functions. In a small CMS I'd written a while back, I was using eval to interpolate variable names in strings. This was a simple way to do "lazy evaluation" on strings I was using as templates. With eval, there was no need to use a special templating syntax - the syntax was PHP's.

Now, with eval turned off, I needed a function to interpolate variables in a string. Here it is:

function interpolate( $string )
{
    foreach ($GLOBALS as $name => $value)
    {
        $string = str_replace( '$'.$name, $value, $string );
    }
    $string = preg_replace( '/[$]\\w+/', '', $string );
    return $string;
}