.\" Copyright 1997 Nicolás Lichtmaier <nick@debian.org>

.\" Created Wed Jul  2 23:27:34 ART 1997

.\"

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.\" Added info on availability, aeb, 971207

.\" Added -lutil remark, 030718

.\" 2008-07-02, mtk, document updwtmpx()

.\"

.TH UPDWTMP 3  2017-09-15 "GNU" "Linux Programmer's Manual"

.SH NAME

updwtmp, logwtmp \- append an entry to the wtmp file

.SH SYNOPSIS

.nf

.B #include <utmp.h>

.PP

.BI "void updwtmp(const char *" wtmp_file ", const struct utmp *" ut );

.BI "void logwtmp(const char *" line ", const char *" name \

", const char *" host );

.fi

.PP

For

.BR logwtmp (),

link with \fI\-lutil\fP.

.SH DESCRIPTION

.BR updwtmp ()

appends the utmp structure

.I ut

to the wtmp file.

.PP

.BR logwtmp ()

constructs a utmp structure using

.IR line ", " name ", " host ,

current time and current process ID.

Then it calls

.BR updwtmp ()

to append the structure to the wtmp file.

.SH FILES

.TP

.I /var/log/wtmp

database of past user logins

.SH ATTRIBUTES

For an explanation of the terms used in this section, see

.BR attributes (7).

.TS

allbox;

lb lb lbw24

l l l.

Interface	Attribute	Value

T{

.BR updwtmp (),

.br

.BR logwtmp ()

T}	Thread safety	MT-Unsafe sig:ALRM timer

.TE

.sp 1

.SH CONFORMING TO

Not in POSIX.1.

Present on Solaris, NetBSD, and perhaps other systems.

.SH NOTES

For consistency with the other "utmpx" functions (see

.BR getutxent (3)),

glibc provides (since version 2.1):

.PP

.in +4n

.EX

.B #include <utmpx.h>

.BI "void updwtmpx (const char *" wtmpx_file ", const struct utmpx *" utx );

.EE

.in

.PP

This function performs the same task as

.BR updwtmp (),

but differs in that it takes a

.I utmpx

structure as its last argument.

.SH SEE ALSO

.BR getutxent (3),

.BR wtmp (5)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I man-pages

project.

A description of the project,

information about reporting bugs,

and the latest version of this page,

can be found at

\%https://www.kernel.org/doc/man\-pages/.