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.\" 34.Dd December 30, 1993 35.Dt WHO 1 36.Os 37.Sh NAME 38.Nm who 39.Nd display who is logged in 40.Sh SYNOPSIS 41.Nm who 42.Op Ar am I 43.Op Ar file 44.Sh DESCRIPTION 45The utility 46.Nm who 47displays 48a list of all users currently logged on, showing for each user 49the login name, 50tty name, the date and time of login, and hostname if not local. 51.Pp 52Available options: 53.Pp 54.Bl -tag -width file 55.It Ar \&am I 56Returns the invoker's real user name. 57.It Ar file 58By default, 59.Nm who 60gathers information from the file 61.Pa /var/run/utmp . 62An alternate 63.Ar file 64may be specified which is usually 65.Pa /var/run/wtmp 66(or 67.Pa /var/run/wtmp.[0-6] 68depending on site policy as 69.Pa wtmp 70can grow quite large and daily versions may or may not 71be kept around after compression by 72.Xr ac 8 ) . 73The 74.Pa wtmp 75file contains a record of every login, logout, 76crash, shutdown and date change 77since 78.Pa wtmp 79was last truncated or 80created. 81.El 82.Pp 83If 84.Pa /var/log/wtmp 85is being used as the file, the user name may be empty 86or one of the special characters '|', '}' and '~'. Logouts produce 87an output line without any user name. For more information on the 88special characters, see 89.Xr utmp 5 . 90.Sh FILES 91.Bl -tag -width /var/log/wtmp.[0-6] -compact 92.It Pa /var/run/utmp 93.It Pa /var/log/wtmp 94.It Pa /var/log/wtmp.[0-6] 95.El 96.Sh SEE ALSO 97.Xr last 1 , 98.Xr users 1 , 99.Xr getuid 2 , 100.Xr utmp 5 101.Sh HISTORY 102A 103.Nm 104command appeared in 105.At v6 . 106