How to use only the UNIX password file with samba ?

[Adam Williams]

>>You want to setup "unix passwd sync", see the smb.conf man page.
>Does this work with shadow passwords?

It should work with anything.  It actually calls the password change 
command that you specify (ex. /usr/bin/passwd) and communicates with it 
via an "expect"-ish script.  If the expect script is a go it then 
proceeds to change the SMB password, else it returns a failure  to change 
the passwd.