4.3BSD-Reno/share/man/cat5/wtmp.0
UTMP(5) 1990 UTMP(5)
NNAAMMEE
utmp, wtmp - login records
SSYYNNOOPPSSIISS
##iinncclluuddee <<uuttmmpp..hh>>
DDEESSCCRRIIPPTTIIOONN
The _u_t_m_p file records information about who is currently
using the system. The file is a sequence of entries with
the following structure, as defined in the include file.
#define UT_NAMESIZE 8
#define UT_LINESIZE 8
#define UT_HOSTSIZE 16
struct utmp {
char ut_line[UT_NAMESIZE];
char ut_name[UT_LINESIZE];
char ut_host[UT_HOSTSIZE];
time_t ut_time;
};
This structure gives the name of the special file associated
with the user's terminal, the user's login name, and the
time of the login in the form of _t_i_m_e(3).
The _w_t_m_p file records all logins and logouts. A null user
name indicates a logout on the associated terminal. Furth-
ermore, the terminal name `~' indicates that the system was
rebooted at the indicated time; in such cases the name will
be ``shutdown''. An adjacent pair of entries with terminal
names `|' and `{' indicate the system-maintained time just
before and just after a _d_a_t_e command has changed the
system's idea of the time. The name for both entries will
be ``date''.
_W_t_m_p is maintained by _l_o_g_i_n(1) and _i_n_i_t(8). Neither of
these programs creates the file, so if it is removed
record-keeping is turned off. It is summarized by _l_a_s_t(1)
and _a_c(8).
FFIILLEESS
/var/run/utmp
/var/log/wtmp
SSEEEE AALLSSOO
last(1), login(1), who(1), ac(8), init(8)
Printed 7/27/90 June 1