Chapter 6. System Data Files and InformationSection 6.1. IntroductionSection 6.2. Password FileSection 6.3. Shadow PasswordsSection 6.4. Group FileSection 6.5. Supplementary Group IDsSection 6.6. Implementation DifferencesSection 6.7. Other Data FilesSection 6.8. Login AccountingSection 6.9. System IdentificationSection 6.10. Time and Date RoutinesSection 6.11. SummaryExercises