can u please provide me a code that displays the login failed details such as date, time,user name and number of times the login failed in a seperate file by using system calls or in shell scripts..
grep Failed /var/log/messages
Depending on your system, you may want to narrow it down more.
As cfajohnson states, this depends on you Operating System.
On many unixes there is a command "lastb" (failed login history) which is related to "last" (successful login history).
man lastb