pam_ttylog is a PAM module to log console output of a login shell. pam_ttylog takes an approach that makes a script-like environment in the PAM session section of /bin/login. Thus, the log files are in a user-unreachable directory and have user-unreadable/unwritable permissions. As PAM module, it doesn't need to modify or replace the original /bin/login, getty, telnet, or libraries for its installation and operation.
