Login

• faillog(5) login failure logging file
• faillog(8) display faillog records or set login failure limits
• lastlog(8) reports the most recent login of all users or of a given user
• login.defs(5) shadow password suite configuration
• login(1) begin session on the system
• newgrp(1) log in to a new group
• nologin(8) politely refuse a login
• sg(1) execute command as different group ID