| .\" Copyright (C) 2010 Michael Krapp |
| .\" |
| .\" This program is free software; you can redistribute it and/or modify |
| .\" it under the terms of the GNU General Public License as published by |
| .\" the Free Software Foundation; either version 2 of the License, or |
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| .\" |
| .\" This program is distributed in the hope that it will be useful, |
| .\" but WITHOUT ANY WARRANTY; without even the implied warranty of |
| .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| .\" GNU General Public License for more details. |
| .\" |
| .\" You should have received a copy of the GNU General Public License |
| .\" along with this program; if not, write to the Free Software |
| .\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| .\" |
| .TH UTMPDUMP 1 "July 2014" "util-linux" "User Commands" |
| .SH NAME |
| utmpdump \- dump UTMP and WTMP files in raw format |
| .SH SYNOPSIS |
| .BR utmpdump " [options]" |
| .RI [ filename ] |
| .SH DESCRIPTION |
| .B utmpdump |
| is a simple program to dump UTMP and WTMP files in raw format, so they |
| can be examined. |
| .B utmpdump |
| reads from stdin unless a |
| .I filename |
| is passed. |
| .SH OPTIONS |
| .TP |
| .BR \-f , " \-\-follow" |
| Output appended data as the file grows. |
| .TP |
| .BR \-o , " \-\-output " \fIfile |
| Write command output to \fIfile\fR instead of standard output. |
| .TP |
| .BR \-r , " \-\-reverse" |
| Undump, write back edited login information into the utmp or wtmp files. |
| .TP |
| .BR \-V , " \-\-version" |
| Display version information and exit. |
| .TP |
| .BR \-h , " \-\-help" |
| Display help text and exit. |
| .SH NOTES |
| .B utmpdump |
| can be useful in cases of corrupted utmp or wtmp entries. It can dump |
| out utmp/wtmp to an ASCII file, which can then be edited to remove |
| bogus entries, and reintegrated using: |
| .PP |
| .RS |
| .B utmpdump -r < ascii_file > wtmp |
| .RE |
| .PP |
| But be warned, |
| .B utmpdump |
| was written for debugging purposes only. |
| .SS File formats |
| .PP |
| The only binary version of the |
| .BR utmp (5) |
| is standardised. Textual dumps may become incompatible in future. |
| .PP |
| The version 2.28 was the last one that printed text output using |
| .BR ctime (3) |
| timestamp format. Newer dumps use millisecond precision ISO-8601 timestamp |
| format in UTC-0 timezone. Conversion from former timestamp format can be |
| made to binary, although attempt to do so can lead the timestamps to drift |
| amount of timezone offset. |
| .SH BUGS |
| You may |
| .B not |
| use the |
| .B \-r |
| option, as the format for the utmp/wtmp files strongly depends on the input |
| format. This tool was |
| .B not |
| written for normal use, but for debugging only. |
| .SH AUTHOR |
| Michael Krapp |
| .SH "SEE ALSO" |
| .BR last (1), |
| .BR w (1), |
| .BR who (1), |
| .BR utmp (5) |
| .SH AVAILABILITY |
| The utmpdump command is part of the util-linux package and is available |
| from |
| .UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/ |
| Linux Kernel Archive |
| .UE . |