The simple virtual terminal locker.
By default, tlock auths $USER using pam. The authentication module used can be
configured in /etc/pam.d/tlock. For example, to enable ldap auth (assuming
ldap is properly configured), change /etc/pam.d/tlock to
auth sufficient pam_unix.so nodelay
auth sufficient pam_ldap.so
If pam is unavailable or undesired, set USE_PAM in Makefile.conf to false
before compiling. In this case, tlock must be suid root to auth.