1.\" $OpenBSD: who.1,v 1.27 2017/06/19 06:05:33 bentley Exp $ 2.\" $NetBSD: who.1,v 1.5 1994/12/07 04:28:47 jtc Exp $ 3.\" 4.\" Copyright (c) 1986, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)who.1 8.2 (Berkeley) 12/30/93 32.\" 33.Dd $Mdocdate: June 19 2017 $ 34.Dt WHO 1 35.Os 36.Sh NAME 37.Nm who 38.Nd display who is logged in 39.Sh SYNOPSIS 40.Nm who 41.Op Fl HmqTu 42.Op Ar file 43.Nm who 44.Cm am i 45.Sh DESCRIPTION 46The 47.Nm 48utility displays a list of all users currently logged on, showing for 49each user the login name, tty name, the date and time of login, and 50hostname if not local. 51.Pp 52The options are as follows: 53.Bl -tag -width Ds 54.It Fl H 55Write column headings above the regular output. 56.It Fl m 57Only print information about the current terminal. 58This is the 59POSIX 60way of saying 61.Nm 62.Cm am i . 63.It Fl q 64(Quick.) 65List only the names and the number of users currently logged on. 66When this option is used, all other options are ignored. 67.It Fl T 68Print a character after the user name indicating the state of the 69terminal line: 70.Sq + 71if the terminal is writable; 72.Sq \- 73if it is not; 74and 75.Sq \&? 76if a bad line is encountered. 77.It Fl u 78Print the idle time for each user. 79.It Cm am i 80Returns the invoker's real user name. 81.It Ar file 82By default, 83.Nm 84gathers information from the file 85.Pa /var/run/utmp . 86An alternate 87.Ar file 88may be specified which is usually 89.Pa /var/log/wtmp 90(or 91.Pa /var/log/wtmp.[0-6] 92depending on site policy as 93.Pa wtmp 94can grow quite large and daily versions may or may not 95be kept around after compression by 96.Xr ac 8 ) . 97The 98.Pa wtmp 99file contains a record of every login, logout, 100crash, shutdown and date change 101since 102.Pa wtmp 103was last truncated or 104created. 105.El 106.Pp 107If 108.Pa /var/log/wtmp 109is being used as the file, the user name may be empty 110or one of the special characters 111.Ql | , 112.Ql } , 113and 114.Ql \&~ . 115Logouts produce an output line without any user name. 116For more information on the special characters, see 117.Xr utmp 5 . 118.Sh FILES 119.Bl -tag -width /var/log/wtmp.[0-6] -compact 120.It Pa /var/run/utmp 121.It Pa /var/log/wtmp 122.It Pa /var/log/wtmp.[0-6] 123.El 124.Sh EXIT STATUS 125.Ex -std who 126.Sh SEE ALSO 127.Xr last 1 , 128.Xr mesg 1 , 129.Xr users 1 , 130.Xr w 1 , 131.Xr getuid 2 , 132.Xr utmp 5 133.Sh STANDARDS 134The 135.Nm 136utility is compliant with the 137.St -p1003.1-2008 138specification. 139.Pp 140The flags 141.Op Fl abdHlpqrst 142are marked by 143.St -p1003.1-2008 144as being an X/Open System Interfaces option. 145Of these, 146.Op Fl abdlprst 147are not supported by this implementation of 148.Nm . 149.Sh HISTORY 150A 151.Nm 152utility appeared in 153.At v1 . 154