CHKLGI, UTILITIES, User Authentication CHKLGI is a routine which allows you to perform the same checks and tasks as LOGINOUT.EXE (the system's login image) when a new process is logged in. You may check for correct passwords, login restrictions, perform ALF (automatic login facility) and proxy-related operations, update the intrusion database and perform system auditing of your logins. CHKLGI shows the use of many less-known system services like SYS$AUDIT_EVENT, SYS$SCAN_INTRUSION, SYS$VERIFY_PROXY, as well as the undocumented image activation service SYS$IMGACT and the license-related services SYS$GRANT_LICENSE, SYS$LOOKUP_ LICENSE and SYS$RELEASE_LICENSE. It also shows how to use item lists in C (for SYS$GETUAI) and some other useful techniques. Finally, the MACRO-32 program, which runs in kernel mode, shows how to scan the PCB (process control block) vector array and how to extract information from these and related data structures.