login-utils/last.1

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  17 .TH "LAST, LASTB" "1" "October 2013" "util-linux" "User Commands"
  18 .SH NAME
  19 last, lastb \- show a listing of last logged in users
  20 .SH SYNOPSIS
  21 .B last
  22 [options]
  23 .RI [ username "...] [" tty ...]
  24 .br
  25 .B lastb
  26 [options]
  27 .RI [ username "...] [" tty ...]
  28 .SH DESCRIPTION
  29 .B last
  30 searches back through the
  31 .I /var/log/wtmp
  32 file (or the file designated by the
  33 .B \-f
  34 option) and displays a list of all users logged in (and out) since that
  35 file was created.  One or more
  36 .IR usernames " and/or " ttys
  37 can be given, in which case
  38 .B last
  39 will show only the entries matching those arguments.  Names of
  40 .I ttys
  41 can be abbreviated, thus
  42 .B last 0
  43 is the same as
  44 .BR "last tty0" .
  45 .PP
  46 When catching a SIGINT signal (generated by the interrupt key, usually
  47 control-C) or a SIGQUIT signal,
  48 .B last
  49 will show how far it has searched through the file; in the case of the
  50 SIGINT signal
  51 .B last
  52 will then terminate.
  53 .PP
  54 The pseudo user
  55 .B reboot
  56 logs in each time the system is rebooted.  Thus
  57 .B last reboot
  58 will show a log of all the reboots since the log file was created.
  59 .PP
  60 .B lastb
  61 is the same as
  62 .BR last ,
  63 except that by default it shows a log of the
  64 .I /var/log/btmp
  65 file, which contains all the bad login attempts.
  66 .SH OPTIONS
  67 .TP
  68 .BR \-a , " \-\-hostlast"
  69 Display the hostname in the last column.  Useful in combination with the
  70 .B \-\-dns
  71 option.
  72 .TP
  73 .BR \-d , " \-\-dns"
  74 For non-local logins, Linux stores not only the host name of the remote
  75 host, but its IP number as well.  This option translates the IP number
  76 back into a hostname.
  77 .TP
  78 .BR \-f , " \-\-file " \fIfile\fR
  79 Tell
  80 .B last
  81 to use a specific \fIfile\fR instead of
  82 .IR /var/log/wtmp .
  83 The
  84 .B \-\-file
  85 option can be given multiple times, and all of the specified files will be
  86 processed.
  87 .TP
  88 .BR \-F , " \-\-fulltimes"
  89 Print full login and logout times and dates.
  90 .TP
  91 .BR \-i , " \-\-ip"
  92 Like
  93 .B \-\-dns ,
  94 but displays the host's IP number instead of the name.
  95 .TP
  96 .BI \- number
  97 .TQ
  98 .BR \-n , " -\-limit " \fInumber\fR
  99 Tell
 100 .B last
 101 how many lines to show.
 102 .TP
 103 .BR \-p , " \-\-present " \fItime\fR
 104 Display the users who were present at the specified time.  This is
 105 like using the options
 106 .BR \-\-since " and " \-\-until
 107 together with the same \fItime\fR.
 108 .TP
 109 .BR \-R , " \-\-nohostname"
 110 Suppresses the display of the hostname field.
 111 .TP
 112 .BR \-s , " \-\-since " \fItime\fR
 113 Display the state of logins since the specified
 114 .IR time .
 115 This is useful, e.g., to easily determine who was logged in at a
 116 particular time.  The option is often combined with
 117 .BR \-\-until .
 118 .TP
 119 .BR \-t , " \-\-until " \fItime\fR
 120 Display the state of logins until the specified
 121 .IR time .
 122 .TP
 123 .BI \-\-time\-format " format"
 124 Define the output timestamp
 125 .I format
 126 to be one of
 127 .IR notime ,
 128 .IR short ,
 129 .IR full ,
 130 or
 131 .IR iso .
 132 The
 133 .I notime
 134 variant will not print any timestamps at all,
 135 .I short
 136 is the default, and
 137 .I full
 138 is the same as the
 139 .B \-\-fulltimes
 140 option.  The
 141 .I iso
 142 variant will display the timestamp in ISO-8601 format.  The ISO format
 143 contains timezone information, making it preferable when printouts are
 144 investigated outside of the system.
 145 .TP
 146 .BR \-w , " \-\-fullnames"
 147 Display full user names and domain names in the output.
 148 .TP
 149 .BR \-x , " \-\-system"
 150 Display the system shutdown entries and run level changes.
 151 .SH TIME FORMATS
 152 The options that take the
 153 .I time
 154 argument understand the following formats:
 155 .TS
 156 l2 l.
 157 YYYYMMDDhhmmss
 158 YYYY-MM-DD hh:mm:ss
 159 YYYY-MM-DD hh:mm        (seconds will be set to 00)
 160 YYYY-MM-DD      (time will be set to 00:00:00)
 161 hh:mm:ss        (date will be set to today)
 162 hh:mm   (date will be set to today, seconds to 00)
 163 now
 164 yesterday       (time is set to 00:00:00)
 165 today   (time is set to 00:00:00)
 166 tomorrow        (time is set to 00:00:00)
 167 +5min
 168 -5days
 169 .TE
 170 .SH FILES
 171 /var/log/wtmp
 172 .br
 173 /var/log/btmp
 174 .SH NOTES
 175 The files
 176 .I wtmp
 177 and
 178 .I btmp
 179 might not be found.  The system only logs information in these files if
 180 they are present.  This is a local configuration issue.  If you want the
 181 files to be used, they can be created with a simple
 182 .BR touch (1)
 183 command (for example,
 184 .IR "touch /var/log/wtmp" ).
 185 .SH AUTHORS
 186 .MT miquels@cistron.nl
 187 Miquel van Smoorenburg
 188 .ME
 189 .SH SEE ALSO
 190 .BR login (1),
 191 .BR wtmp (5),
 192 .BR init (8),
 193 .BR shutdown (8)
 194 .SH AVAILABILITY
 195 The last command is part of the util-linux package and is available from
 196 .UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
 197 Linux Kernel Archive
 198 .UE .