cat /var/log/secure and grep patter on CentOS Linux

1. change to root

$ su -

2. grep pattern to authntication failure login user root

$ cat /var/log/secure | grep -E 'authenctication failure.*rhost=.*user=root'

 

 

 

 

 

 

# AND  syntax

3. grep pattern  for OR syntax

$ cat /var/log/secure | grep -E 'authentication failure|user=root'