linuxidc@ubuntu:~/linuxidc.com$ echo "root,hello world,linuxidc.com" | tr -d "a-h"
root,llo worl,linuxi.om
linuxidc@ubuntu:~/linuxidc.com$ echo "root,hello world,linuxidc.com,2019" | tr -d "a-z"
, ,.,2019
linuxidc@ubuntu:~/linuxidc.com$ echo "root,hello world,linuxidc.com,2019" | tr -d "0-9"
root,hello world,linuxidc.com,
