utmp, wtmp, .ilog

Purpose

     Contains user and accounting information.

Synopsis

     #include <utmp.h>

Description

     When  a  user logs  in  successfully,  the login  program
     writes entries  in /etc/utmp, the record  of users logged
     into the system, and in /usr/adm/wtmp (if it exists), for
     use in accounting.  On invalid  login attempts (due to an
     incorrect login name or password), login makes entries in
     the /etc/.ilog file.  When you log  in as user root or su
     and the /etc/.ilog  file is not empty, you  see a message
     advising you to check the /etc/.ilog file for a record of
     unsuccessful login attempts.

     The  records in  these files  follow the  utmp structure,
     which is defined in the utmp.h header file:

          #define UTMP_FILE  "/etc/utmp"
          #define WTMP_FILE  "/usr/adm/wtmp"
          #define ILOG_FILE  "/etc/.ilog"

          #define ut_name  ut_user
          #define ut_id    ut_line

          struct utmp  {
               char ut_user[8];         /* User login name */
               char ut_line[12];        /* device name (console, lnxx) */
               short  ut_pid;           /* process id */
               short  ut_type;          /* type of entry */
               struct exit_status {
                  short e_termination;  /* Process termination status */
                  short e_exit;         /* Process exit status */
                  } ut_exit;            /* The exit status of a process */
                                        /* marked as DEAD_PROCESS. */
                  time_t  ut_time;      /* time entry was made */
       &c2ins.
                  stnet  termio ut_termio; /* save login termio paramters */
       &c2off.
       };

          /* Definitions for ut_type */

          #define EMPTY          0
          #define RUN_LVL        1
          #define BOOT_TIME      2
          #define OLD_TIME       3
          #define NEW_TIME       4

          #define INIT_PROCESS   5     /* Process spawned by "init" */
          #define LOGIN_PROCESS  6     /* A "getty" process waiting for login */
          #define USER_PROCESS   7     /* A user process */
          #define DEAD_PROCESS   8
          #define ACCOUNTING     9
       &c2del.
          #define UTMAXTYPE ACCOUNTING  /* Largest legal value of ut_type */
       &c2off.
       &c2ins.
          #define TSH_PROCESS  10
          #define UTMAXTYPE TSH_PROCESS  /* Largest legal value of ut_type */
       &c2off.

          /* Special strings or formats used in the "ut_line" field when */
          /* accounting for something other than a process. */
          /* No string for the ut_line field can be more than 11 chars + */
          /* a NULL in length. */

          #define RUNLVL_MSG     "run-level ?"
          #define BOOT_MSG       "system boot"
          #define OTIME_MSG      "old time"
          #define NTIME_MSG      "new time"

Files

     /etc/utmp       Record of users logged into the system
     /usr/adm/wtmp   Accounting information
     /etc/.ilog      Record of invalid logins.

Related Information

     The  login,  who, and  write  commands  in AIX  Operating
     System Commands Reference.