1.\" Copyright (c) 1986, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)who.1 8.2 (Berkeley) 12/30/93 33.\" $Id$ 34.\" 35.Dd December 30, 1993 36.Dt WHO 1 37.Os 38.Sh NAME 39.Nm who 40.Nd display who is logged in 41.Sh SYNOPSIS 42.Nm who 43.Op Ar am I 44.Op Ar file 45.Sh DESCRIPTION 46The utility 47.Nm who 48displays 49a list of all users currently logged on, showing for each user 50the login name, 51tty name, the date and time of login, and hostname if not local. 52.Pp 53Available options: 54.Pp 55.Bl -tag -width file 56.It Ar \&am I 57Returns the invoker's real user name. 58.It Ar file 59By default, 60.Nm who 61gathers information from the file 62.Pa /var/run/utmp . 63An alternate 64.Ar file 65may be specified which is usually 66.Pa /var/run/wtmp 67(or 68.Pa /var/run/wtmp.[0-6] 69depending on site policy as 70.Pa wtmp 71can grow quite large and daily versions may or may not 72be kept around after compression by 73.Xr ac 8 ) . 74The 75.Pa wtmp 76file contains a record of every login, logout, 77crash, shutdown and date change 78since 79.Pa wtmp 80was last truncated or 81created. 82.El 83.Pp 84If 85.Pa /var/log/wtmp 86is being used as the file, the user name may be empty 87or one of the special characters '|', '}' and '~'. Logouts produce 88an output line without any user name. For more information on the 89special characters, see 90.Xr utmp 5 . 91.Sh FILES 92.Bl -tag -width /var/log/wtmp.[0-6] -compact 93.It Pa /var/run/utmp 94.It Pa /var/log/wtmp 95.It Pa /var/log/wtmp.[0-6] 96.El 97.Sh SEE ALSO 98.Xr last 1 , 99.Xr users 1 , 100.Xr getuid 2 , 101.Xr utmp 5 102.Sh HISTORY 103A 104.Nm 105command appeared in 106.At v1 . 107