PHP 得到根目录 和 删除文件

<?php
$file = "test.txt";
if (!unlink($file))
  {
  echo ("Error deleting $file");
  }
else
  {
  echo ("Deleted $file");
  }
?>



php可以获得站点的根目录
function GetRootPath()
{
        $sRealPath = realpath( './' ) ;

        $sSelfPath = $_SERVER['PHP_SELF'] ;
        $sSelfPath = substr( $sSelfPath, 0, strrpos( $sSelfPath, '/' ) ) ;

        return substr( $sRealPath, 0, strlen( $sRealPath ) - strlen( $sSelfPath ) ) ;
}


通过$_SERVER["DOCUMENT_ROOT"]变量取虚拟目录