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.Dd December 5, 2009
.Os
.Dt ULOG_GETUTXENT 3
.Sh NAME
.Nm ulog_getutxent ,
.Nm ulog_getutxline ,
.Nm ulog_pututxline ,
.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 struct ulog_utmpx *
.Fn ulog_getutxline "const struct ulog_utmpx *line"
.Ft struct ulog_utmpx *
.Fn ulog_pututxline "const struct ulog_utmpx *utmpx"
.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_id[];	/* Private data. */
	char	ut_line[];	/* TTY device. */
	char	ut_host[];	/* Remote hostname. */
	pid_t	ut_pid;		/* Process identifier. */
	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_id
Private data that can be used to later identify the record.
This implementation is not capable of storing this value on disk.
.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_pid
Process identifier of the session leader of the login session.
This implementation is not capable of storing this value on disk.
.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 BOOT_TIME
Identifies time of system boot.
.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 INIT_PROCESS
Identifies a process spawned by the init process.
.It Dv LOGIN_PROCESS
Identifies the session leader of a logged-in user.
.It Dv DEAD_PROCESS
Identifies a session leader who has exited.
.It Dv SHUTDOWN_TIME
Identifies time when system was shut down.
.El
.It Fa ut_tv
Timestamp indicating when the entry was last modified.
.El
.Pp
This implementation guarantees all strings returned in the structure to
be null terminated.
.Pp
The
.Fn ulog_getutxent
function reads the next entry from the utmp file, opening the file if
necessary.
The
.Fn ulog_getutxline
function reads entries from the utmp file, until finding an entry which
shares the same
.Fa ut_line
as the structure
.Fa line .
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
and
.Fn ulog_getutxline
functions read from the beginning of the file until and EOF is
encountered.
.Pp
The
.Fn ulog_pututxline
function writes a new entry to the file.
.Sh RETURN VALUES
The
.Fn ulog_getutxent
and
.Fn ulog_getutxline
functions return a null pointer on EOF or error.
.Sh SEE ALSO
.Xr ulog_login 3 ,
.Xr ulog_setutxfile 3 ,
.Xr utmp 5
.Sh STANDARDS
This interface is similar to
.In utmpx.h
described in
.St -p1003.1-2008 ,
but incompatible.
The underlying file format does not allow a correctly behaving
implementation of the standardized interface.
.Pp
This programming interface has been designed to ease the migration
towards
.In utmpx.h .
If
.Dv _ULOG_POSIX_NAMES
is set before inclusion of
.In ulog.h ,
it is also possible to use the
.Vt utmpx
structure and the
.Fn getutxent ,
.Fn getutxline ,
.Fn pututxline ,
.Fn setutxent
and
.Fn endutxent
functions.
.Sh HISTORY
These functions appeared in
.Fx 9.0 .