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| 32 | .\" @(#)utmp.5 8.2 (Berkeley) 3/17/94 |
| 33 | .\" $FreeBSD: src/share/man/man5/utmp.5,v 1.9.2.8 2001/12/17 11:30:15 ru Exp $ |
| 34 | .\" $DragonFly: src/share/man/man5/utmp.5,v 1.3 2006/05/26 19:39:40 swildner Exp $ |
| 35 | .\" |
| 36 | .Dd November 14, 2001 |
| 37 | .Dt UTMP 5 |
| 38 | .Os |
| 39 | .Sh NAME |
| 40 | .Nm utmp , |
| 41 | .Nm wtmp , |
| 42 | .Nm lastlog |
| 43 | .Nd login records |
| 44 | .Sh SYNOPSIS |
| 45 | .In sys/types.h |
| 46 | .In utmp.h |
| 47 | .Sh DESCRIPTION |
| 48 | The file |
| 49 | .In utmp.h |
| 50 | declares the structures used to record information about current |
| 51 | users in the file |
| 52 | .Nm , |
| 53 | logins and logouts in the file |
| 54 | .Nm wtmp , |
| 55 | and last logins in the file |
| 56 | .Nm lastlog . |
| 57 | The time stamps of date changes, shutdowns and reboots are also logged in |
| 58 | the |
| 59 | .Nm wtmp |
| 60 | file. |
| 61 | .Bd -literal -offset indent |
| 62 | #define _PATH_UTMP "/var/run/utmp" |
| 63 | #define _PATH_WTMP "/var/log/wtmp" |
| 64 | #define _PATH_LASTLOG "/var/log/lastlog" |
| 65 | |
| 66 | #define UT_NAMESIZE 16 |
| 67 | #define UT_LINESIZE 8 |
| 68 | #define UT_HOSTSIZE 16 |
| 69 | |
| 70 | struct lastlog { |
| 71 | time_t ll_time; /* When user logged in */ |
| 72 | char ll_line[UT_LINESIZE]; /* Terminal line name */ |
| 73 | char ll_host[UT_HOSTSIZE]; /* Host user came from */ |
| 74 | }; |
| 75 | |
| 76 | struct utmp { |
| 77 | char ut_line[UT_LINESIZE]; /* Terminal line name */ |
| 78 | char ut_name[UT_NAMESIZE]; /* User's login name */ |
| 79 | char ut_host[UT_HOSTSIZE]; /* Host user came from */ |
| 80 | time_t ut_time; /* When user logged in */ |
| 81 | }; |
| 82 | .Ed |
| 83 | .Pp |
| 84 | The |
| 85 | .Nm lastlog |
| 86 | file is a linear array of |
| 87 | .Vt lastlog |
| 88 | structures indexed by a user's |
| 89 | .Tn UID . |
| 90 | The |
| 91 | .Nm |
| 92 | file is a linear array of |
| 93 | .Vt utmp |
| 94 | structures indexed by a terminal line number |
| 95 | (see |
| 96 | .Xr ttyslot 3 ) . |
| 97 | The |
| 98 | .Nm wtmp |
| 99 | file consists of |
| 100 | .Vt utmp |
| 101 | structures and is a binary log file, |
| 102 | that is, grows linearly at its end. |
| 103 | .Pp |
| 104 | Each time a user logs in, the |
| 105 | .Xr login 1 |
| 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 (unless the login is |
| 113 | .Em quiet , |
| 114 | see |
| 115 | .Xr login 1 ) . |
| 116 | The |
| 117 | .Xr login 1 |
| 118 | program then records the new login time in the file |
| 119 | .Nm lastlog . |
| 120 | .Pp |
| 121 | After the new |
| 122 | .Vt lastlog |
| 123 | record is written, |
| 124 | .\" the |
| 125 | .\" .Xr libutil 3 |
| 126 | .\" routine |
| 127 | the file |
| 128 | .Nm |
| 129 | is opened and the |
| 130 | .Vt utmp |
| 131 | record for the user is inserted. |
| 132 | This record remains there until |
| 133 | the user logs out at which time it is deleted. |
| 134 | The |
| 135 | .Nm |
| 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 1 |
| 145 | program opens the file |
| 146 | .Nm wtmp , |
| 147 | and appends the user's |
| 148 | .Vt utmp |
| 149 | record. |
| 150 | The user's subsequent logout from the terminal |
| 151 | line is marked by a special |
| 152 | .Vt utmp |
| 153 | record with |
| 154 | .Va ut_line |
| 155 | set accordingly, |
| 156 | .Va ut_time |
| 157 | updated, but |
| 158 | .Va ut_name |
| 159 | and |
| 160 | .Va ut_host |
| 161 | both empty |
| 162 | (see |
| 163 | .Xr init 8 ) . |
| 164 | The |
| 165 | .Nm wtmp |
| 166 | file is used by the programs |
| 167 | .Xr last 1 |
| 168 | and |
| 169 | .Xr ac 8 . |
| 170 | .Pp |
| 171 | In the event of a date change, a shutdown or reboot, the |
| 172 | following items are logged in the |
| 173 | .Nm wtmp |
| 174 | file. |
| 175 | .Pp |
| 176 | .Bl -tag -width ".Li shutdown" -compact |
| 177 | .It Li reboot |
| 178 | .It Li shutdown |
| 179 | A system reboot or shutdown has been initiated. |
| 180 | The character |
| 181 | .Ql \&~ |
| 182 | is placed in the field |
| 183 | .Va ut_line , |
| 184 | and |
| 185 | .Li reboot |
| 186 | or |
| 187 | .Li shutdown |
| 188 | in the field |
| 189 | .Va ut_name |
| 190 | (see |
| 191 | .Xr shutdown 8 |
| 192 | and |
| 193 | .Xr reboot 8 ) . |
| 194 | .Pp |
| 195 | .It Li date |
| 196 | The system time has been manually or automatically updated |
| 197 | (see |
| 198 | .Xr date 1 ) . |
| 199 | The command name |
| 200 | .Li date |
| 201 | is recorded in the field |
| 202 | .Va ut_name . |
| 203 | In the field |
| 204 | .Va ut_line , |
| 205 | the character |
| 206 | .Ql \&| |
| 207 | indicates the time prior to the change, and the character |
| 208 | .Ql \&{ |
| 209 | indicates the new time. |
| 210 | .El |
| 211 | .Sh NOTES |
| 212 | The |
| 213 | .Nm wtmp |
| 214 | file can grow rapidly on busy systems, so daily or weekly rotation |
| 215 | is recommended. |
| 216 | It is maintained by |
| 217 | .Xr newsyslog 8 . |
| 218 | .Pp |
| 219 | If any one of these files does not exist, it is not created by |
| 220 | .Xr login 1 . |
| 221 | They must be created manually. |
| 222 | .Pp |
| 223 | The supplied |
| 224 | .Xr login 3 , |
| 225 | .Xr logout 3 , |
| 226 | and |
| 227 | .Xr logwtmp 3 |
| 228 | utility functions should be used to perform |
| 229 | the standard actions on the |
| 230 | .Nm |
| 231 | and |
| 232 | .Nm wtmp |
| 233 | files in order to maintain the portability across |
| 234 | systems with different formats of those files. |
| 235 | .Sh FILES |
| 236 | .Bl -tag -width ".Pa /var/log/lastlog" -compact |
| 237 | .It Pa /var/run/utmp |
| 238 | The |
| 239 | .Nm |
| 240 | file. |
| 241 | .It Pa /var/log/wtmp |
| 242 | The |
| 243 | .Nm wtmp |
| 244 | file. |
| 245 | .It Pa /var/log/lastlog |
| 246 | The |
| 247 | .Nm lastlog |
| 248 | file. |
| 249 | .El |
| 250 | .Sh SEE ALSO |
| 251 | .Xr last 1 , |
| 252 | .Xr login 1 , |
| 253 | .Xr w 1 , |
| 254 | .Xr who 1 , |
| 255 | .Xr login 3 , |
| 256 | .Xr logout 3 , |
| 257 | .Xr logwtmp 3 , |
| 258 | .Xr ttyslot 3 , |
| 259 | .Xr ac 8 , |
| 260 | .Xr init 8 |
| 261 | .Sh HISTORY |
| 262 | A |
| 263 | .Nm |
| 264 | and |
| 265 | .Nm wtmp |
| 266 | file format appeared in |
| 267 | .At v6 . |
| 268 | The |
| 269 | .Nm lastlog |
| 270 | file format appeared in |
| 271 | .Bx 3.0 . |