man/utmp.5

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  34 .\"     @(#)utmp.5      8.2 (Berkeley) 3/17/94
  35 .\"
  36 .Dd March 17, 1994
  37 .Dt UTMP 5
  38 .Os BSD 4
  39 .Sh NAME
  40 .Nm utmp ,
  41 .Nm wtmp ,
  42 .Nm lastlog
  43 .Nd login records (DEPRECATED)
  44 .Sh SYNOPSIS
  45 .Fd #include <utmp.h>
  46 .Sh DESCRIPTION
  47 The interfaces in file
  48 .Aq Pa utmp.h
  49 are all
  50 .Sy DEPRECIATED
  51 and are only provided for compatibility with previous releases of Mac OS X.
  52 See
  53 .Xr pututxline 3
  54 and
  55 .Xr utmpx 5
  56 for the supported interfaces.
  57 .Pp
  58 .Aq Pa utmp.h
  59 declares the structures used to record information about current
  60 users in the file
  61 .Nm utmp ,
  62 logins and logouts in the file
  63 .Nm wtmp ,
  64 and last logins in the file
  65 .Nm lastlog .
  66 The time stamps of date changes, shutdowns and reboots are also logged in
  67 the
  68 .Nm wtmp
  69 file.
  70 .Pp
  71 These files can grow rapidly on busy systems, daily or weekly rotation
  72 is recommended.
  73 If any of these files do not exist, it is not created.
  74 These
  75 files must be created manually and are normally maintained in either the script
  76 .Pa /etc/daily
  77 or the script
  78 .Pa /etc/weekly .
  79 (See
  80 .Xr cron 8 . )
  81 .Bd -literal -offset indent
  82 #define _PATH_UTMP      "/var/run/utmp"
  83 #define _PATH_WTMP      "/var/log/wtmp"
  84 #define _PATH_LASTLOG   "/var/log/lastlog"
  85
  86 #define UT_NAMESIZE     8
  87 #define UT_LINESIZE     8
  88 #define UT_HOSTSIZE     16
  89
  90 struct lastlog {
  91         time_t  ll_time;
  92         char    ll_line[UT_LINESIZE];
  93         char    ll_host[UT_HOSTSIZE];
  94 };
  95
  96 struct utmp {
  97         char    ut_line[UT_LINESIZE];
  98         char    ut_name[UT_NAMESIZE];
  99         char    ut_host[UT_HOSTSIZE];
 100         time_t  ut_time;
 101 };
 102 .Ed
 103 .Pp
 104 Each time a user logs in, the
 105 .Xr login
 106 program looks up the user's
 107 .Tn UID
 108 in the file
 109 .Nm lastlog.
 110 If it is found, the timestamp of the last time the user logged
 111 in, the terminal line and the hostname
 112 are written to the standard output. (Providing the login is not
 113 .Em quiet ,
 114 see
 115 .Xr login 1 . )
 116 The
 117 .Xr login
 118 program then records the new login time in the file
 119 .Nm lastlog .
 120 .Pp
 121 After the new
 122 .Fa lastlog
 123 record is written ,
 124 .\" the
 125 .\" .Xr libutil 3
 126 .\" routine
 127 the file
 128 .Nm utmp
 129 is opened and the
 130 .Fa utmp
 131 record for the user inserted.
 132 This record remains there until
 133 the user logs out at which time it is deleted.
 134 The
 135 .Nm utmp
 136 file is used by the programs
 137 .Xr rwho 1 ,
 138 .Xr users 1 ,
 139 .Xr w 1 ,
 140 and
 141 .Xr who 1 .
 142 .Pp
 143 Next, the
 144 .Xr login
 145 program opens the file
 146 .Nm wtmp ,
 147 and appends the user's
 148 .Fa utmp
 149 record.
 150 The same
 151 .Fa utmp
 152 record, with an updated time stamp is later appended
 153 to the file when the user logs out. (See
 154 .Xr launchd 8 . )
 155 The
 156 .Nm wtmp
 157 file is used by the programs
 158 .Xr last 1
 159 and
 160 .Xr ac 8 .
 161 .Pp
 162 In the event of a date change, a shutdown or reboot, the
 163 following items are logged in the
 164 .Nm wtmp
 165 file.
 166 .Pp
 167 .Bl -tag -width shutdownxx -compact
 168 .It Li reboot
 169 .It Li shutdown
 170 A system reboot or shutdown has been initiated.
 171 The character
 172 .Ql \&~
 173 is placed in the field
 174 .Fa ut_line ,
 175 and
 176 .Li reboot
 177 or
 178 .Li shutdown
 179 in the field
 180 .Fa ut_name .
 181 (See
 182 .Xr shutdown 8
 183 and
 184 .Xr reboot 8 . )
 185 .Pp
 186 .It Li date
 187 The system time has been manually or automatically updated.
 188 (See
 189 .Xr date 1 . )
 190 The command name
 191 .Xr date
 192 is recorded in the field
 193 .Fa ut_name .
 194 In the field
 195 .Fa ut_line ,
 196 the character
 197 .Ql \\*(Ba
 198 indicates the time prior to the change, and the character
 199 .Ql \&{
 200 indicates the new time.
 201 .El
 202 .Sh FILES
 203 .Bf Sy
 204 (These files no longer exist in 10.5 or later.)
 205 .Ef
 206 .Pp
 207 .Bl -tag -width /var/log/lastlog -compact
 208 .It Pa /var/run/utmp
 209 The
 210 .Nm utmp file.
 211 .It Pa /var/log/wtmp
 212 The
 213 .Nm wtmp file.
 214 .It Pa /var/log/lastlog
 215 The
 216 .Nm lastlog file.
 217 .El
 218 .Sh SEE ALSO
 219 .Xr last 1 ,
 220 .Xr login 1 ,
 221 .Xr who 1 ,
 222 .Xr ac 8 ,
 223 .Xr launchd 8
 224 .Sh HISTORY
 225 A
 226 .Nm utmp
 227 and
 228 .Nm wtmp
 229 file format appeared in
 230 .At v6 .
 231 The
 232 .Nm lastlog
 233 file format appeared in
 234 .Bx 3.0 .