shell判断全部都是数字（shell学习笔记六）

[root@localhost shell_project]# aa=123

 [root@localhost shell_project]# bb=$(echo $aa | sed 's/[0-9]//g')

 [root@localhost shell_project]# echo $bb
[root@localhost shell_project]# 

 [root@localhost shell_project]# aa=adc

 [root@localhost shell_project]# bb=$(echo $aa | sed 's/[0-9]//g')

 [root@localhost shell_project]# echo $bb

 adc

 [root@localhost shell_project]#