$source ="$http://www.baidu.com/call.scv$";echo trim($source,"$");
$source ='$http://www.baidu.com/call.scv$'; 这里应该是单引号
echo trim($source,'$');
$source ='$http://www.baidu.com/call.scv$';
error_reporting(E_ALL ^ E_NOTICE);$source ="$http://www.baidu.com/call.scv$";echo $source;
$source ='$http://www.baidu.com/call.scv$';echo trim($source,"$");