| 1 | .\" @(#)who.1 6.1 (Berkeley) %G% |
| 2 | .\" |
| 3 | .TH WHO 1 "" |
| 4 | .AT 3 |
| 5 | .SH NAME |
| 6 | who \- who is on the system |
| 7 | .SH SYNOPSIS |
| 8 | .B who |
| 9 | [ who-file ] [ |
| 10 | .B "am I" |
| 11 | ] |
| 12 | .SH DESCRIPTION |
| 13 | .I Who, |
| 14 | without an argument, |
| 15 | lists the login name, terminal name, and login time |
| 16 | for each current UNIX user. |
| 17 | .PP |
| 18 | Without an argument, |
| 19 | .I who |
| 20 | examines the |
| 21 | .I /etc/utmp |
| 22 | file to obtain its information. |
| 23 | If a file is given, that file is examined. |
| 24 | Typically the given file will be /usr/adm/wtmp, |
| 25 | which contains a record of all the logins since it |
| 26 | was created. |
| 27 | Then |
| 28 | .I who |
| 29 | lists |
| 30 | logins, logouts, and crashes since the creation of |
| 31 | the wtmp file. |
| 32 | Each login is listed with user name, |
| 33 | terminal name (with `/dev/' |
| 34 | suppressed), |
| 35 | and date and time. |
| 36 | When an argument is given, logouts produce a similar line without a user name. |
| 37 | Reboots produce a line with `x' in the place of the device name, |
| 38 | and a fossil time indicative of when the system went down. |
| 39 | .PP |
| 40 | With two arguments, |
| 41 | as in `who am I' (and also `who are you'), |
| 42 | .I who |
| 43 | tells who you are logged in as. |
| 44 | .SH FILES |
| 45 | /etc/utmp |
| 46 | .SH "SEE ALSO" |
| 47 | getuid(2), utmp(5) |