freebsd_amp_hwpstate/lib/libulog/ulog_getutxent.3

121 lines
3.5 KiB
Groff

.\" Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd December 2, 2009
.Os
.Dt ULOG_GETUTXENT 3
.Sh NAME
.Nm ulog_getutxent ,
.Nm ulog_setutxent ,
.Nm ulog_endutxent
.Nd read user login records
.Sh LIBRARY
.Lb libulog
.Sh SYNOPSIS
.In ulog.h
.Ft struct ulog_utmpx *
.Fn ulog_getutxent "void"
.Ft void
.Fn ulog_setutxent "void"
.Ft void
.Fn ulog_endutxent "void"
.Sh DESCRIPTION
The
.Fn ulog_getutxent
function returns a pointer to an object, with the following structure,
containing stored information of an active user login session.
.Bd -literal
struct ulog_utmpx {
char *ut_user; /* Username. */
char *ut_line; /* TTY device. */
char *ut_host; /* Remote hostname. */
short ut_type; /* Type of entry. */
struct timeval ut_tv; /* Timestamp. */
};
.Ed
.Pp
The fields are as follows:
.Bl -tag -width ut_user
.It Fa ut_user
The username of the logged in user.
.It Fa ut_line
The pathname of the TTY device, without the leading
.Pa /dev/
directory.
.It Fa ut_host
An optional hostname of a remote system, if the login session is
provided through a networked login service.
.It Fa ut_type
The
.Fa ut_type
field contains the type of the message, which may have one of the
following values:
.Bl -tag -width SHUTDOWN_TIME
.It Dv EMPTY
No valid user accounting information.
.It Dv OLD_TIME
Identifies time when system clock changed.
.It Dv NEW_TIME
Identifies time after system clock changed.
.It Dv USER_PROCESS
Identifies a process.
.It Dv DEAD_PROCESS
Identifies a session leader who has exited.
.It Dv SHUTDOWN_TIME
Identifies time when system was shut down.
.It Dv REBOOT_TIME
Identifies time when system was rebooted.
.El
.It Fa ut_tv
Timestamp indicating when the entry was last modified.
.El
.Pp
The
.Fn ulog_getutxent
function reads the next entry from the utmp file, opening the file if
necessary.
The
.Fn ulog_setutxent
opens the file, closing it first if already opened.
The
.Fn ulog_endutxent
function closes any open files.
.Pp
The
.Fn ulog_getutxent
function reads from the beginning of the file until and EOF is
encountered.
.Sh RETURN VALUES
The
.Fn ulog_getutxent
function returns a null pointer on EOF or error.
.Sh SEE ALSO
.Xr ulog_login 3 ,
.Xr utmp 5
.Sh HISTORY
These functions appeared in
.Fx 9.0 .