utmp(4)                                                                utmp(4)


NAME
     utmp, wtmp - utmp and wtmp entry formats

SYNOPSIS
     #include <utmp.h>

DESCRIPTION
     These files, which hold user and accounting information for such commands
     as who, last, write, and login, contain entries with the following
     structure, defined in utmp.h:

     #define UTMP_FILE   "/var/adm/utmp"
     #define WTMP_FILE   "/var/adm/wtmp"
     #define ut_name     ut_user
     struct     utmp {
        char    ut_user[8];      /* user login name */
        char    ut_id[4];        /* /etc/inittab id (created by */
                                 /* process that puts entry in utmp) */
        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;               /* exit status of a process */
                                 /* marked as DEAD_PROCESS */
        time_t  ut_time;         /* time entry was made */
     };

     /*  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
     #define UTMAXTYPE     ACCOUNTING /* max legal value of ut_type */

     /*  Below are the special strings or formats used in the "ut_line" */
     /*  field when accounting for something other than a process.  */
     /*  Strings for the ut_line field must be no more than 11 chars +  */
     /*  terminating NULL in length.  */
     #define RUNLVL_MSG     "run-level %c"
     #define BOOT_MSG       "system boot"
     #define OTIME_MSG      "old time"
     #define NTIME_MSG      "new time"


FILES
     /var/adm/utmp
     /var/adm/wtmp

WARNING
     All changes to /var/adm/wtmp must also be logged in /var/adm/wtmpx.  Most
     commands that extract information from these files silently discard all
     wtmpx entries without wtmp complements.

SEE ALSO
     w(1), login(1), who(1), last(1), utmpx(4), write(1), getut(3C),
     getutx(3C), chkutent(1M)


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