1UTMPDUMP(1)                      User Commands                     UTMPDUMP(1)
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NAME

6       utmpdump - dump UTMP and WTMP files in raw format
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SYNOPSIS

9       utmpdump [options] filename
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DESCRIPTION

12       utmpdump is a simple program to dump UTMP and WTMP files in raw format,
13       so they can be examined. utmpdump reads from stdin unless a filename is
14       passed.
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OPTIONS

17       -f, --follow
18           Output appended data as the file grows.
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20       -o, --output file
21           Write command output to file instead of standard output.
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23       -r, --reverse
24           Undump, write back edited login information into the utmp or wtmp
25           files.
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27       -h, --help
28           Display help text and exit.
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30       -V, --version
31           Print version and exit.
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NOTES

34       utmpdump can be useful in cases of corrupted utmp or wtmp entries. It
35       can dump out utmp/wtmp to an ASCII file, which can then be edited to
36       remove bogus entries, and reintegrated using:
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38          utmpdump -r < ascii_file > wtmp
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40       But be warned, utmpdump was written for debugging purposes only.
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42   File formats
43       Only the binary version of the utmp(5) is standardised. Textual dumps
44       may become incompatible in future.
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46       The version 2.28 was the last one that printed text output using
47       ctime(3) timestamp format. Newer dumps use millisecond precision
48       ISO-8601 timestamp format in UTC-0 timezone. Conversion from former
49       timestamp format can be made to binary, although attempt to do so can
50       lead the timestamps to drift amount of timezone offset.
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BUGS

53       You may not use the -r option, as the format for the utmp/wtmp files
54       strongly depends on the input format. This tool was not written for
55       normal use, but for debugging only.
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AUTHORS

58       Michael Krapp
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SEE ALSO

61       last(1), w(1), who(1), utmp(5)
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REPORTING BUGS

64       For bug reports, use the issue tracker at
65       https://github.com/util-linux/util-linux/issues.
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AVAILABILITY

68       The utmpdump command is part of the util-linux package which can be
69       downloaded from Linux Kernel Archive
70       <https://www.kernel.org/pub/linux/utils/util-linux/>.
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74util-linux 2.38                   2022-02-17                       UTMPDUMP(1)
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