utmpdump - dump UTMP and WTMP files in raw format


   utmpdump [options] [filename]


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


   -f, --follow
          Output appended data as the file grows.

   -o, --output file
          Write command output to file instead of standard output.

   -r, --reverse
          Undump,  write  back  edited  login information into the utmp or
          wtmp files.

   -V, --version
          Display version information and exit.

   -h, --help
          Display help text and exit.


   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:

          utmpdump -r < ascii_file > wtmp

   But be warned, utmpdump was written for debugging purposes only.

   File formats
   The only binary version of the utmp(5) is standardised.  Textual  dumps
   may become incompatible in future.

   The  version  2.28  was  the  last  one  that printed text output using
   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.


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


   Michael Krapp


   last(1), w(1), who(1), utmp(5)


   The utmpdump command is part of the util-linux package and is available
   from Linux Kernel  Archive  ftp://ftp.kernel.org/pub/linux/utils/util-


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