$re = '/(?P<open>(?P<quote>[\'"])|\()(?P<relativeFile>(?:\.\.\/)+.*?)(?P<params>[#\?].*?|)?(?P<close>\k<quote>|\))/x';
$str = ' src: url(\'../fonts/levibrush-webfont.eot\');
src: url(\'../fonts/levibrush-webfont.eot?#iefix\') format(\'embedded-opentype\'), url(\'../fonts/levibrush-webfont.woff\') format(\'woff\'), url(\'../fonts/levibrush-webfont.ttf\') format(\'truetype\'), url(\'../fonts/levibrush-webfont.svg#LeviBrushRegular\') format(\'svg\');
html {background:url(../images/bg-body.png) repeat scroll 0 0; color:;}
"../../../../images/image.png"(../../../../images/image.png)\'../../../../images/image.png\' "../../../../images/image.png" \'../../../../images/image.png\'"../../../../images/image.png"\'../../../../images/image.png\'';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php