who(1) [v7 man page]

WHO(1)							      General Commands Manual							    WHO(1)

NAME

       who  -  who is on the system

SYNOPSIS

       who [ who-file ] [ am I ]

DESCRIPTION

       Who, without an argument, lists the login name, terminal name, and login time for each current UNIX user.

       Without	an argument, who examines the /etc/utmp file to obtain its information.  If a file is given, that file is examined.  Typically the
       given file will be /usr/adm/wtmp, which contains a record of all the logins since it was created.  Then	who  lists  logins,  logouts,  and
       crashes	since  the  creation of the wtmp file.	Each login is listed with user name, terminal name (with `/dev/' suppressed), and date and
       time.  When an argument is given, logouts produce a similar line without a user name.  Reboots produce a line with `x' in the place of  the
       device name, and a fossil time indicative of when the system went down.

       With two arguments, as in `who am I' (and also `who are you'), who tells who you are logged in as.

FILES

       /etc/utmp

SEE ALSO

       getuid(2), utmp(5)

																	    WHO(1)

utmp(4) 						     Kernel Interfaces Manual							   utmp(4)

NAME

       utmp, wtmp - Login records

SYNOPSIS

       #include <utmp.h>

DESCRIPTION

       The  utmp  file	records information about who is currently using the system.  The file is a sequence of utmp entries, as defined in struct
       utmp in the utmp.h file.

       The utmp structure gives the name of the special file associated with the user's terminal, the user's login name, and the time of the login
       in the form of time(3).	The ut_type field is the type of entry, which can specify several symbolic constant values. The symbolic constants
       are defined in the utmp.h file.

       The wtmp file records all logins and logouts.  A null user name indicates a logout on the associated terminal.  A terminal referenced  with
       a tilde (~) indicates that the system was rebooted at the indicated time.  The adjacent pair of entries with terminal names referenced by a
       vertical bar (|) or a right brace (}) indicate the system-maintained time just before and just after a date command has	changed  the  sys-
       tem's time frame.

       The  wtmp  file is maintained by login(1) and init(8).  Neither of these programs creates the file, so, if it is removed, record keeping is
       turned off.  See ac(8) for information on the file.

FILES

RELATED INFORMATION

       ac(8), init(8), last(8), lastcomm(8), login(1), who(1), wtmpconvert(8).	delim off

																	   utmp(4)