utmp(F)                         19 June 1992                         utmp(F)


 Name

    utmp, wtmp - format of utmp and wtmp entries

 Syntax

    #include <sys/types.h>
    #include <utmp.h>

 Description

    These files, which hold user and accounting information for such commands
    as who(C), write(C), and login(M), have the following structure as
    defined by <utmp.h>:

    #define UTMP_FILE      ``/etc/utmp''
    #define WTMP_FILE      ``/etc/wtmp''
    #define ut_name        ut_user

    struct  utmp {
            char    ut_user[8];             /* User login name */
            char    ut_id[4];               /* usually line # */
            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 */
    };

    /* 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   /* Largest legal value of ut_type */

    /* 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 %c"
    #define BOOT_MSG        "system boot"
    #define OTIME_MSG       "old time"
    #define NTIME_MSG       "new time"

 Files

    /usr/include/utmp.h
    /etc/utmp
    /etc/wtmp

 See also

    getut(S), login(M), who(C), write(C)

 Standards conformance

    utmp and wtmp are conformant with:

    X/Open Portability Guide, Issue 3, 1989.