[unix-history] / usr / man / man5 / utmp.5

.TH UTMP 5 
.SH NAME
utmp, wtmp \- login records
.SH SYNOPSIS
.B #include <utmp.h>
.SH DESCRIPTION
The
.I utmp
file allows one to discover information about who is currently
using UNIX.
The file is a sequence of entries with the following
structure declared in the include file:
.RS
.PP
.nf
.so /usr/include/utmp.h
.fi
.RE
.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
.IR time (2).
.PP
The
.I wtmp
file records all logins and logouts.
Its format is exactly like
.I utmp
except that
a null user name indicates a logout on the associated
terminal.
Furthermore, the terminal name `~' indicates that the
system was rebooted at the indicated time;
the adjacent pair of entries with terminal names
`\^|\^' and `}' indicate the system-maintained time
just before and just after a
.I date
command has changed the system's idea of the time.
.PP
.I Wtmp
is maintained by
.IR login (1)
and
.IR init (8).
Neither of these programs creates the file,
so if it is removed record-keeping is turned off.
It is summarized by
.IR ac (1).
.SH FILES
/etc/utmp
.br
/usr/adm/wtmp
.SH "SEE ALSO"
login(1), init(8), who(1), ac(1)
Commit	Line	Data
e6817382 BJ	1	.TH UTMP 5
	2	.SH NAME
	3	utmp, wtmp \- login records
	4	.SH SYNOPSIS
	5	.B #include <utmp.h>
	6	.SH DESCRIPTION
	7	The
	8	.I utmp
	9	file allows one to discover information about who is currently
	10	using UNIX.
	11	The file is a sequence of entries with the following
	12	structure declared in the include file:
	13	.RS
	14	.PP
	15	.nf
	16	.so /usr/include/utmp.h
	17	.fi
	18	.RE
	19	.PP
	20	This structure gives the name of the special file
	21	associated with the user's terminal, the user's login name,
	22	and the time of the login in the form of
	23	.IR time (2).
	24	.PP
	25	The
	26	.I wtmp
	27	file records all logins and logouts.
	28	Its format is exactly like
	29	.I utmp
	30	except that
	31	a null user name indicates a logout on the associated
	32	terminal.
	33	Furthermore, the terminal name `~' indicates that the
	34	system was rebooted at the indicated time;
	35	the adjacent pair of entries with terminal names
	36	`\^\|\^' and `}' indicate the system-maintained time
	37	just before and just after a
	38	.I date
	39	command has changed the system's idea of the time.
	40	.PP
	41	.I Wtmp
	42	is maintained by
	43	.IR login (1)
	44	and
	45	.IR init (8).
	46	Neither of these programs creates the file,
	47	so if it is removed record-keeping is turned off.
	48	It is summarized by
	49	.IR ac (1).
	50	.SH FILES
	51	/etc/utmp
	52	.br
	53	/usr/adm/wtmp
	54	.SH "SEE ALSO"
	55	login(1), init(8), who(1), ac(1)