In CentOS, lastb lists user commands that fail to log on to the system.

Function description: lists information about users who failed to log on to the system. Syntax: lastb [-adRx] [-f & lt; Record File & gt;] [-n & lt; display columns & gt;] [account name...] [terminal number...] note: execute the lastb command separately. it reads the file named btmp in the/var/log directory and records the username list for logon failures recorded in the file, all are displayed. Parameter:-a displays the host name or IP address from which to log on to the system at the end.

Function description: lists information about users who failed to log on to the system.

Syntax: lastb [-adRx] [-f <记录文件> ] [-N <显示列数> ] [Account name...] [terminal number...]

Note: execute the lastb command separately. it will read the file named btmp in the/var/log directory and put the file content
All user names that have failed to log on are displayed.

Parameters:
-A displays the host name or IP address from which to log on to the system in the last row.
-D. convert the IP address to the host name.
-F <记录文件> Specifies the record file.
-N <显示列数> Or- <显示列数> Set the number of columns displayed in the list.
-R does not display the host name or IP address used to log on to the system.
-X displays information such as system shutdown, reboot, and change of execution level.