utmp.5

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 5 代码 · 共 58 行

.\" SCCSID: @(#)utmp.5	8.1	9/11/90
.TH utmp 5 
.SH Name
utmp, wtmp \- login records
.SH Syntax
.B #include <utmp.h>
.SH Description
.NXR "utmp file" "format"
.NXR "wtmp file" "format"
.NXR "login" "recording"
The
.PN utmp
file records information about who is currently using the system.
The file is a sequence of entries with the following
structure declared in the include file:
.EX 0
struct utmp {
        char    ut_line[8];             /* tty name */
        char    ut_name[8];             /* user id */
        char    ut_host[16];            /* host name, if remote */
        long    ut_time;                /* time on */
};
.EE
.PP
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 
.MS time 3c .
.PP
The
.PN wtmp
file records all logins and logouts.
A null user name indicates a logout on the associated terminal.
A terminal referenced with a tilde (~) indicates that the
system was rebooted at the indicated time.
The adjacent pair of entries with terminal names
referenced by a vertical bar (|) or a right brace (})
indicate the system-maintained
time just before and just after a
.PN date
command has changed the system's timeframe.
.PP
The
.PN wtmp
file is maintained by 
.MS login 1
and 
.MS init 8 .
Neither of these programs creates the file,
so, if it is removed, record-keeping is turned off.  It is summarized by
.MS ac 8 .
.SH Files
.PN /etc/utmp
.br
.PN /usr/adm/wtmp
.SH See Also
last(1), lastcomm(1), login(1), who(1), ac(8), init(8)