PAM account, auth, password, session source code and modules + config of /etc/nsswitch.conf

[hanasaki <hanasaki@hanaden.com>]

Any pointers on where to find skeleton source files, and a make file for
	PAM account, auth, password, session
in C? perl? other recommended programing languages?
???

Also, how is it that Linux knows to use LDAP auth if its installed?  The 
config file for the ldap auth is one thing.  It points to the server and 
root.  Is it /etc/nsswitch.conf that tells pam_unix.so to use ldap auth? 
 Ditto for account, password and session.

Thanks.