check files or directories size
$ du -sk /home/zy
87 /home/zy
-s calculates the total disk usage for all specified files and directories.
-k calculates in 1024-byte unites, by default, it will calculate in block count(512-byte in most)
$ du -ak /home/zy
23 ../zy/m1
52 ../zy/m2
1 ../zy/crm/global_brand_prod.bcp
4 ../zy/crm/crm.ksh
1 ../zy/crm/in_files
7 ../zy/crm/l_global_brand_prod.sql
12 ../zy/crm
87 ../zy
-a calculates each files and directories specified.


