Get the time of the previous day and the use of the Shell's ${!3} and eval

Example 1:

[email protected] opt]# cat a.sh #!/bin/bashsource/opt/b.txtaa=${!1}echo $AA [[email protected] opt]# cat B.txt Abc=1[[em AIL protected] opt]# sh a.sh ABC1

Example 2:

[email protected] opt]# cat a.sh #!/bin/basha=1b=aecho ${b}echo ${!b}eval echo \$ $b [[email protected] opt]# sh a.sh a11

Get the time of the previous day

Date-d -1day +%y%m%d

This article is from "YHT's operations Notes" blog, please make sure to keep this source http://yht1990.blog.51cto.com/9014030/1905981

Get the time of the previous day and the use of the Shell's ${!3} and eval