login configuration file

[Mohammed Khalid Ansari <khalid ncst ernet in>]

Hi

I am confused regarding PAM, I read the manual for PAM but could not get the 
proper explaination and not a single complete example. Will anyone explain me 
using the following example...

I have the following config file for login...

auth       required     /lib/security/pam_securetty.so
auth       required     /lib/security/pam_stack.so service=system-auth
auth       required     /lib/security/pam_nologin.so
account    required     /lib/security/pam_stack.so service=system-auth
password   required     /lib/security/pam_stack.so service=system-auth
session    required     /lib/security/pam_stack.so service=system-auth
session    optional     /lib/security/pam_console.so


Now explain me what each line one by one means in the file.

with regards....