How to view the folder size in Linux (CentOS)

Reference http://zhidao.baidu.com/link?url= Orfdgdhvya1psday6ql-igpbwtvcs5ar9bc543ztr1hlidfcd42nytnbplal2phvmpokfmkjrfzgvkdgfq8ti5y3mrr_35rkor6luq5zpjy here,

Du-sh. The system only displays the total space occupied by the current folder, as shown (note that in CentOS, the size of the folder, if directly using LS ll and other commands, it will be shown to the size of 4096 bytes)

Du-a. All files are displayed. All files, including subfolders, are also displayed: (This is generally not used)

To view the size of a folder's space consumption

How to view the folder size in Linux (CentOS)