[root@localhost ~]# mkdir dy[root@localhost ~]# cd dy[root@localhost dy]# touch dzp dzp2 dzp3 dzp34 dzpcang dzpbols[root@localhost dy]# lsdzp dzp2 dzp3 dzp34 dzpbols dzpcang[root@localhost dy]# la dzpbash: la: command not found...[root@localhost dy]# ls dzpdzp[root@localhost dy]# ls dzp*dzp dzp2 dzp3 dzp34 dzpbols dzpcang[root@localhost dy]# ls dzp?dzp2 dzp3[root@localhost dy]# ls dzp[0-9]dzp2 dzp3[root@localhost dy]# ls dzp[0-9][0-9]dzp34[root@localhost dy]# ls dzp[^0-9]ls: cannot access dzp[^0-9]: No such file or directory[root@localhost dy]# touch dzpa[root@localhost dy]# ls dzp[^0-9]dzpa[root@localhost dy]# ls dzp[^0-9]*dzpa dzpbols dzpcang

[root@localhost dy]# echo lsls[root@localhost dy]# echo dzpdzp[root@localhost dy]# aa=123[root@localhost dy]# echo $aa123[root@localhost dy]# echo '$aa'$aa[root@localhost dy]# echo "$aa"123[root@localhost dy]# aa=ls[root@localhost dy]# echo "$aa"ls[root@localhost dy]# aa=`ls`[root@localhost dy]# echo "$aa"dzpdzp2dzp3dzp34dzpadzpbolsdzpcang[root@localhost dy]# bb=$(ls)[root@localhost dy]# echo $bbdzp dzp2 dzp3 dzp34 dzpa dzpbols dzpcang[root@localhost dy]# echo $(date)Sat Jul 15 17:23:31 CST 2017[root@localhost dy]# echo /$bb$bb